CD9

Tetraspanin proteins are involved in a multitude of biological processes such as adhesion, motility, membrane fusion, signaling and protein trafficking.{{cite journal | vauthors = Hemler ME | title = Tetraspanin functions and associated microdomains | journal = Nature Reviews. Molecular Cell Biology | volume = 6 | issue = 10 | pages = 801–11 | date = October 2005 | pmid = 16314869 | doi = 10.1038/nrm1736 | s2cid = 5906694 }} Tetraspanins play a role in many biological processes because of their ability to interact with many different proteins including interactions between each other. Their distinct palmitoylation sites allow them to organize on the membrane into tetraspanin-enriched microdomains (TEM). These TEMs are thought to play a role in many cellular processes including exosome biogenesis.{{cite journal | vauthors = Perez-Hernandez D, Gutiérrez-Vázquez C, Jorge I, López-Martín S, Ursa A, Sánchez-Madrid F, Vázquez J, Yáñez-Mó M | display-authors = 6 | title = The intracellular interactome of tetraspanin-enriched microdomains reveals their function as sorting machineries toward exosomes | journal = The Journal of Biological Chemistry | volume = 288 | issue = 17 | pages = 11649–61 | date = April 2013 | pmid = 23463506 | pmc = 3636856 | doi = 10.1074/jbc.M112.445304 | doi-access = free }} CD9 is commonly used as a marker for exosomes as it is contained on their surface.{{cite journal | vauthors = Lai RC, Arslan F, Lee MM, Sze NS, Choo A, Chen TS, Salto-Tellez M, Timmers L, Lee CN, El Oakley RM, Pasterkamp G, de Kleijn DP, Lim SK | display-authors = 6 | title = Exosome secreted by MSC reduces myocardial ischemia/reperfusion injury | journal = Stem Cell Research | volume = 4 | issue = 3 | pages = 214–22 | date = May 2010 | pmid = 20138817 | doi = 10.1016/j.scr.2009.12.003 | doi-access = free }}{{cite journal | vauthors = Sumiyoshi N, Ishitobi H, Miyaki S, Miyado K, Adachi N, Ochi M | title = The role of tetraspanin CD9 in osteoarthritis using three different mouse models | journal = Biomedical Research | volume = 37 | issue = 5 | pages = 283–291 | date = October 2016 | pmid = 27784871 | doi = 10.2220/biomedres.37.283 | doi-access = free }}

However, in some cases CD9 plays a larger role in the ability of exosomes to be more or less pathogenic. Shown in HIV-1 infection, exosomes are able to enhance HIV-1 entry through tetraspanin CD9 and CD81.{{cite journal | vauthors = Sims B, Farrow AL, Williams SD, Bansal A, Krendelchtchikov A, Matthews QL | title = Tetraspanin blockage reduces exosome-mediated HIV-1 entry | journal = Archives of Virology | volume = 163 | issue = 6 | pages = 1683–1689 | date = June 2018 | pmid = 29429034 | pmc = 5958159 | doi = 10.1007/s00705-018-3737-6 }} However, expression of CD9 on the cellular membrane seems to decrease the viral entry of HIV-1.{{cite journal | vauthors = Gordón-Alonso M, Yañez-Mó M, Barreiro O, Alvarez S, Muñoz-Fernández MA, Valenzuela-Fernández A, Sánchez-Madrid F | title = Tetraspanins CD9 and CD81 modulate HIV-1-induced membrane fusion | journal = Journal of Immunology | volume = 177 | issue = 8 | pages = 5129–37 | date = October 2006 | pmid = 17015697 | doi = 10.4049/jimmunol.177.8.5129 | doi-access = free }}{{cite book | vauthors = Thali M | title = HIV Interactions with Host Cell Proteins | chapter = The roles of tetraspanins in HIV-1 replication | volume = 339 | pages = 85–102 | date = 2009 | pmid = 20012525 | pmc = 4067973 | doi = 10.1007/978-3-642-02175-6_5 | publisher = Springer Berlin Heidelberg | isbn = 978-3-642-02174-9 | series = Current Topics in Microbiology and Immunology }}

CD9 has a diverse role in cellular processes as it has also been shown to trigger platelet activation and aggregation.{{cite journal | vauthors = Rubinstein E, Billard M, Plaisance S, Prenant M, Boucheix C | title = Molecular cloning of the mouse equivalent of CD9 antigen | journal = Thrombosis Research | volume = 71 | issue = 5 | pages = 377–83 | date = September 1993 | pmid = 8236164 | doi = 10.1016/0049-3848(93)90162-h }} It forms a alphaIIbbeta3-CD9-CD63 complex on the surface of platelets that interacts directly with other cells such as neutrophils which may assist in immune response.{{cite journal | vauthors = Israels SJ, McMillan-Ward EM, Easton J, Robertson C, McNicol A | title = CD63 associates with the alphaIIb beta3 integrin-CD9 complex on the surface of activated platelets | journal = Thrombosis and Haemostasis | volume = 85 | issue = 1 | pages = 134–41 | date = January 2001 | pmid = 11204565 | doi = 10.1055/s-0037-1612916 | s2cid = 28721583 }}{{cite journal | vauthors = Yun SH, Sim EH, Goh RY, Park JI, Han JY | title = Platelet Activation: The Mechanisms and Potential Biomarkers | journal = BioMed Research International | volume = 2016 | pages = 9060143 | date = 2016 | pmid = 27403440 | pmc = 4925965 | doi = 10.1155/2016/9060143 | doi-access = free }} In addition, the protein appears to promote muscle cell fusion and support myotube maintenance.{{cite journal | vauthors = Tachibana I, Hemler ME | title = Role of transmembrane 4 superfamily (TM4SF) proteins CD9 and CD81 in muscle cell fusion and myotube maintenance | journal = The Journal of Cell Biology | volume = 146 | issue = 4 | pages = 893–904 | date = August 1999 | pmid = 10459022 | pmc = 2156130 | doi = 10.1083/jcb.146.4.893 }}{{cite journal | vauthors = Charrin S, Latil M, Soave S, Polesskaya A, Chrétien F, Boucheix C, Rubinstein E | title = Normal muscle regeneration requires tight control of muscle cell fusion by tetraspanins CD9 and CD81 | journal = Nature Communications | volume = 4 | pages = 1674 | date = 2013 | pmid = 23575678 | doi = 10.1038/ncomms2675 | bibcode = 2013NatCo...4.1674C | doi-access = free }} Also, playing a key role in egg-sperm fusion during mammalian fertilization. While oocytes are ovulated, CD9-deficient oocytes do not properly fuse with sperm upon fertilization.{{cite journal | vauthors = Le Naour F, Rubinstein E, Jasmin C, Prenant M, Boucheix C | title = Severely reduced female fertility in CD9-deficient mice | journal = Science | volume = 287 | issue = 5451 | pages = 319–21 | date = January 2000 | pmid = 10634790 | doi = 10.1126/science.287.5451.319 | bibcode = 2000Sci...287..319L }} CD9 is located in the microvillar membrane of the oocytes and also appears to intervene in maintaining the normal shape of oocyte microvilli.{{cite journal | vauthors = Runge KE, Evans JE, He ZY, Gupta S, McDonald KL, Stahlberg H, Primakoff P, Myles DG | display-authors = 6 | title = Oocyte CD9 is enriched on the microvillar membrane and required for normal microvillar shape and distribution | journal = Developmental Biology | volume = 304 | issue = 1 | pages = 317–25 | date = April 2007 | pmid = 17239847 | doi = 10.1016/j.ydbio.2006.12.041 | doi-access = }}

CD9 can also modulate cell adhesion{{cite journal | vauthors = Machado-Pineda Y, Cardeñes B, Reyes R, López-Martín S, Toribio V, Sánchez-Organero P, Suarez H, Grötzinger J, Lorenzen I, Yáñez-Mó M, Cabañas C | display-authors = 6 | title = CD9 Controls Integrin α5β1-Mediated Cell Adhesion by Modulating Its Association With the Metalloproteinase ADAM17 | journal = Frontiers in Immunology | volume = 9 | pages = 2474 | date = 2018 | pmid = 30455686 | pmc = 6230984 | doi = 10.3389/fimmu.2018.02474 | doi-access = free }} and migration.{{cite journal | vauthors = Blake DJ, Martiszus JD, Lone TH, Fenster SD | title = Ablation of the CD9 receptor in human lung cancer cells using CRISPR/Cas alters migration to chemoattractants including IL-16 | journal = Cytokine | volume = 111 | pages = 567–570 | date = November 2018 | pmid = 29884309 | doi = 10.1016/j.cyto.2018.05.038 | pmc = 8711597 | s2cid = 46997236 }}{{cite journal | vauthors = Miki Y, Yashiro M, Okuno T, Kitayama K, Masuda G, Hirakawa K, Ohira M | title = CD9-positive exosomes from cancer-associated fibroblasts stimulate the migration ability of scirrhous-type gastric cancer cells | journal = British Journal of Cancer | volume = 118 | issue = 6 | pages = 867–877 | date = March 2018 | pmid = 29438363 | pmc = 5886122 | doi = 10.1038/bjc.2017.487 }} This function makes CD9 of interest when studying cancer and cancer metastasis. However, it seems CD9 has a varying role in different types of cancers. Studies showed that CD9 expression levels have an inverse correlation to metastatic potential or patient survival. The over expression of CD9 was shown to decrease metastasis in certain types of melanoma, breast, lung, pancreas and colon carcinomas.{{cite journal | vauthors = Mimori K, Mori M, Shiraishi T, Tanaka S, Haraguchi M, Ueo H, Shirasaka C, Akiyoshi T | display-authors = 6 | title = Expression of ornithine decarboxylase mRNA and c-myc mRNA in breast tumours | journal = International Journal of Oncology | volume = 12 | issue = 3 | pages = 597–601 | date = March 1998 | pmid = 9472098 | doi = 10.3892/ijo.12.3.597 }}{{cite journal | vauthors = Higashiyama M, Taki T, Ieki Y, Adachi M, Huang CL, Koh T, Kodama K, Doi O, Miyake M | display-authors = 6 | title = Reduced motility related protein-1 (MRP-1/CD9) gene expression as a factor of poor prognosis in non-small cell lung cancer | journal = Cancer Research | volume = 55 | issue = 24 | pages = 6040–4 | date = December 1995 | pmid = 8521390 | doi = 10.1016/0169-5002(96)87780-4 }}{{cite journal | vauthors = Ikeyama S, Koyama M, Yamaoko M, Sasada R, Miyake M | title = Suppression of cell motility and metastasis by transfection with human motility-related protein (MRP-1/CD9) DNA | journal = The Journal of Experimental Medicine | volume = 177 | issue = 5 | pages = 1231–7 | date = May 1993 | pmid = 8478605 | pmc = 2191011 | doi = 10.1084/jem.177.5.1231 }}{{cite journal | vauthors = Sho M, Adachi M, Taki T, Hashida H, Konishi T, Huang CL, Ikeda N, Nakajima Y, Kanehiro H, Hisanaga M, Nakano H, Miyake M | display-authors = 6 | title = Transmembrane 4 superfamily as a prognostic factor in pancreatic cancer | journal = International Journal of Cancer | volume = 79 | issue = 5 | pages = 509–16 | date = October 1998 | pmid = 9761121 | doi = 10.1002/(sici)1097-0215(19981023)79:5<509::aid-ijc11>3.0.co;2-x | s2cid = 19842716 }}{{cite journal | vauthors = Ovalle S, Gutiérrez-López MD, Olmo N, Turnay J, Lizarbe MA, Majano P, Molina-Jiménez F, López-Cabrera M, Yáñez-Mó M, Sánchez-Madrid F, Cabañas C | display-authors = 6 | title = The tetraspanin CD9 inhibits the proliferation and tumorigenicity of human colon carcinoma cells | journal = International Journal of Cancer | volume = 121 | issue = 10 | pages = 2140–52 | date = November 2007 | pmid = 17582603 | doi = 10.1002/ijc.22902 | s2cid = 22410504 | doi-access = free }} However in other studies, CD9 has been shown to increase migration or be highly expressed in metastatic cancers in various cell lines such as lung cancer, scirrhous-type gastric cancer, hepatocellular carcinoma,{{cite journal | vauthors = Lin Q, Peng S, Yang Y | title = Inhibition of CD9 expression reduces the metastatic capacity of human hepatocellular carcinoma cell line MHCC97-H | journal = International Journal of Oncology | volume = 53 | issue = 1 | pages = 266–274 | date = July 2018 | pmid = 29749468 | doi = 10.3892/ijo.2018.4381 | doi-access = free }} acute lymphoblastic leukemia,{{cite journal | vauthors = Liang P, Miao M, Liu Z, Wang H, Jiang W, Ma S, Li C, Hu R | display-authors = 6 | title = CD9 expression indicates a poor outcome in acute lymphoblastic leukemia | journal = Cancer Biomarkers | volume = 21 | issue = 4 | pages = 781–786 | date = 2018 | pmid = 29286918 | doi = 10.3233/CBM-170422 }} and breast cancer. Suggesting based on the cancer CD9 can be a tumor suppressor or promotor. {{cite journal | vauthors = Zöller M | title = Tetraspanins: push and pull in suppressing and promoting metastasis | journal = Nature Reviews. Cancer | volume = 9 | issue = 1 | pages = 40–55 | date = January 2009 | pmid = 19078974 | doi = 10.1038/nrc2543 | s2cid = 32065330 }} It has also been suggested that CD9 has an effect on the ability for cancer cells to develop chemoresistance.

Additionally, CD9 has been shown to block adhesion of Staphylococcus aureus to wounds. The adhesion is essential for infection of the wound.{{cite journal | vauthors = Ventress JK, Partridge LJ, Read RC, Cozens D, MacNeil S, Monk PN | title = Peptides from Tetraspanin CD9 Are Potent Inhibitors of Staphylococcus Aureus Adherence to Keratinocytes | journal = PLOS ONE | volume = 11 | issue = 7 | pages = e0160387 | date = 2016-07-28 | pmid = 27467693 | pmc = 4965146 | doi = 10.1371/journal.pone.0160387 | bibcode = 2016PLoSO..1160387V | doi-access = free }} This suggests that CD9 could be of possible use to as treatment for skin infection by Staphylococcus aureus.

CD9 has been shown to interact with:

{{div col|colwidth=20em}}

• CD117,{{cite journal | vauthors = Anzai N, Lee Y, Youn BS, Fukuda S, Kim YJ, Mantel C, Akashi M, Broxmeyer HE | display-authors = 6 | title = C-kit associated with the transmembrane 4 superfamily proteins constitutes a functionally distinct subunit in human hematopoietic progenitors | journal = Blood | volume = 99 | issue = 12 | pages = 4413–21 | date = June 2002 | pmid = 12036870 | doi = 10.1182/blood.v99.12.4413 }}
• CD29{{cite journal | vauthors = Mazzocca A, Carloni V, Sciammetta S, Cordella C, Pantaleo P, Caldini A, Gentilini P, Pinzani M | display-authors = 6 | title = Expression of transmembrane 4 superfamily (TM4SF) proteins and their role in hepatic stellate cell motility and wound healing migration | journal = Journal of Hepatology | volume = 37 | issue = 3 | pages = 322–30 | date = September 2002 | pmid = 12175627 | doi = 10.1016/s0168-8278(02)00175-7 }}
• CD46,{{cite journal | vauthors = Lozahic S, Christiansen D, Manié S, Gerlier D, Billard M, Boucheix C, Rubinstein E | title = CD46 (membrane cofactor protein) associates with multiple beta1 integrins and tetraspans | journal = European Journal of Immunology | volume = 30 | issue = 3 | pages = 900–7 | date = March 2000 | pmid = 10741407 | doi = 10.1002/1521-4141(200003)30:3<900::AID-IMMU900>3.0.CO;2-X | doi-access = free }}
• CD49c,{{cite journal | vauthors = Park KR, Inoue T, Ueda M, Hirano T, Higuchi T, Maeda M, Konishi I, Fujiwara H, Fujii S | display-authors = 6 | title = CD9 is expressed on human endometrial epithelial cells in association with integrins alpha(6), alpha(3) and beta(1) | journal = Molecular Human Reproduction | volume = 6 | issue = 3 | pages = 252–7 | date = March 2000 | pmid = 10694273 | doi = 10.1093/molehr/6.3.252 | doi-access = free }}{{cite journal | vauthors = Hirano T, Higuchi T, Ueda M, Inoue T, Kataoka N, Maeda M, Fujiwara H, Fujii S | display-authors = 6 | title = CD9 is expressed in extravillous trophoblasts in association with integrin alpha3 and integrin alpha5 | journal = Molecular Human Reproduction | volume = 5 | issue = 2 | pages = 162–7 | date = February 1999 | pmid = 10065872 | doi = 10.1093/molehr/5.2.162 | doi-access = free }}
• CD81,{{cite journal | vauthors = Radford KJ, Thorne RF, Hersey P | title = CD63 associates with transmembrane 4 superfamily members, CD9 and CD81, and with beta 1 integrins in human melanoma | journal = Biochemical and Biophysical Research Communications | volume = 222 | issue = 1 | pages = 13–8 | date = May 1996 | pmid = 8630057 | doi = 10.1006/bbrc.1996.0690 }}{{cite journal | vauthors = Horváth G, Serru V, Clay D, Billard M, Boucheix C, Rubinstein E | title = CD19 is linked to the integrin-associated tetraspans CD9, CD81, and CD82 | journal = The Journal of Biological Chemistry | volume = 273 | issue = 46 | pages = 30537–43 | date = November 1998 | pmid = 9804823 | doi = 10.1074/jbc.273.46.30537 | doi-access = free }}
• PTGFRN,{{cite journal | vauthors = Charrin S, Le Naour F, Oualid M, Billard M, Faure G, Hanash SM, Boucheix C, Rubinstein E | display-authors = 6 | title = The major CD9 and CD81 molecular partner. Identification and characterization of the complexes | journal = The Journal of Biological Chemistry | volume = 276 | issue = 17 | pages = 14329–37 | date = April 2001 | pmid = 11278880 | doi = 10.1074/jbc.M011297200 | doi-access = free }}{{cite journal | vauthors = Stipp CS, Orlicky D, Hemler ME | title = FPRP, a major, highly stoichiometric, highly specific CD81- and CD9-associated protein | journal = The Journal of Biological Chemistry | volume = 276 | issue = 7 | pages = 4853–62 | date = February 2001 | pmid = 11087758 | doi = 10.1074/jbc.M009859200 | doi-access = free }}
• TSPAN4.{{cite journal | vauthors = Tachibana I, Bodorova J, Berditchevski F, Zutter MM, Hemler ME | title = NAG-2, a novel transmembrane-4 superfamily (TM4SF) protein that complexes with integrins and other TM4SF proteins | journal = The Journal of Biological Chemistry | volume = 272 | issue = 46 | pages = 29181–9 | date = November 1997 | pmid = 9360996 | doi = 10.1074/jbc.272.46.29181 | doi-access = free }}
• CD63
• ADAM17 {{cite journal | vauthors = Gutiérrez-López MD, Gilsanz A, Yáñez-Mó M, Ovalle S, Lafuente EM, Domínguez C, Monk PN, González-Alvaro I, Sánchez-Madrid F, Cabañas C | display-authors = 6 | title = The sheddase activity of ADAM17/TACE is regulated by the tetraspanin CD9 | journal = Cellular and Molecular Life Sciences | volume = 68 | issue = 19 | pages = 3275–92 | date = October 2011 | pmid = 21365281 | doi = 10.1007/s00018-011-0639-0 | s2cid = 23682577 | pmc = 11115118 }}
• CD81{{cite journal | vauthors = Gustafson-Wagner E, Stipp CS | title = The CD9/CD81 tetraspanin complex and tetraspanin CD151 regulate α3β1 integrin-dependent tumor cell behaviors by overlapping but distinct mechanisms | journal = PLOS ONE | volume = 8 | issue = 4 | pages = e61834 | date = 2013 | pmid = 23613949 | pmc = 3629153 | doi = 10.1371/journal.pone.0061834 | bibcode = 2013PLoSO...861834G | doi-access = free }}

{{Div col end}}

• Tetraspanin
• Myogenesis
• Fertilisation

{{reflist}}

{{refbegin}}

• {{cite journal | vauthors = Horejsí V, Vlcek C | title = Novel structurally distinct family of leucocyte surface glycoproteins including CD9, CD37, CD53 and CD63 | journal = FEBS Letters | volume = 288 | issue = 1–2 | pages = 1–4 | date = August 1991 | pmid = 1879540 | doi = 10.1016/0014-5793(91)80988-F | s2cid = 26316623 | doi-access = }}
• {{cite journal | vauthors = Berditchevski F | title = Complexes of tetraspanins with integrins: more than meets the eye | journal = Journal of Cell Science | volume = 114 | issue = Pt 23 | pages = 4143–51 | date = December 2001 | doi = 10.1242/jcs.114.23.4143 | pmid = 11739647 }}
• {{cite journal | vauthors = Ninomiya H, Sims PJ | title = The human complement regulatory protein CD59 binds to the alpha-chain of C8 and to the "b"domain of C9 | journal = The Journal of Biological Chemistry | volume = 267 | issue = 19 | pages = 13675–80 | date = July 1992 | doi = 10.1016/S0021-9258(18)42266-1 | pmid = 1377690 | doi-access = free }}
• {{cite journal | vauthors = Miyake M, Koyama M, Seno M, Ikeyama S | title = Identification of the motility-related protein (MRP-1), recognized by monoclonal antibody M31-15, which inhibits cell motility | journal = The Journal of Experimental Medicine | volume = 174 | issue = 6 | pages = 1347–54 | date = December 1991 | pmid = 1720807 | pmc = 2119050 | doi = 10.1084/jem.174.6.1347 }}
• {{cite journal | vauthors = Boucheix C, Benoit P, Frachet P, Billard M, Worthington RE, Gagnon J, Uzan G | title = Molecular cloning of the CD9 antigen. A new family of cell surface proteins | journal = The Journal of Biological Chemistry | volume = 266 | issue = 1 | pages = 117–22 | date = January 1991 | doi = 10.1016/S0021-9258(18)52410-8 | pmid = 1840589 | doi-access = free }}
• {{cite journal | vauthors = Iwamoto R, Senoh H, Okada Y, Uchida T, Mekada E | title = An antibody that inhibits the binding of diphtheria toxin to cells revealed the association of a 27-kDa membrane protein with the diphtheria toxin receptor | journal = The Journal of Biological Chemistry | volume = 266 | issue = 30 | pages = 20463–9 | date = October 1991 | doi = 10.1016/S0021-9258(18)54947-4 | pmid = 1939101 | doi-access = free }}
• {{cite journal | vauthors = Benoit P, Gross MS, Frachet P, Frézal J, Uzan G, Boucheix C, Nguyen VC | title = Assignment of the human CD9 gene to chromosome 12 (region P13) by use of human specific DNA probes | journal = Human Genetics | volume = 86 | issue = 3 | pages = 268–72 | date = January 1991 | pmid = 1997380 | doi = 10.1007/bf00202407 | s2cid = 27178985 }}
• {{cite journal | vauthors = Lanza F, Wolf D, Fox CF, Kieffer N, Seyer JM, Fried VA, Coughlin SR, Phillips DR, Jennings LK | display-authors = 6 | title = cDNA cloning and expression of platelet p24/CD9. Evidence for a new family of multiple membrane-spanning proteins | journal = The Journal of Biological Chemistry | volume = 266 | issue = 16 | pages = 10638–45 | date = June 1991 | doi = 10.1016/S0021-9258(18)99271-9 | pmid = 2037603 | doi-access = free }}
• {{cite journal | vauthors = Higashihara M, Takahata K, Yatomi Y, Nakahara K, Kurokawa K | title = Purification and partial characterization of CD9 antigen of human platelets | journal = FEBS Letters | volume = 264 | issue = 2 | pages = 270–4 | date = May 1990 | pmid = 2358073 | doi = 10.1016/0014-5793(90)80265-K | s2cid = 42129059 }}
• {{cite journal | vauthors = Masellis-Smith A, Shaw AR | title = CD9-regulated adhesion. Anti-CD9 monoclonal antibody induce pre-B cell adhesion to bone marrow fibroblasts through de novo recognition of fibronectin | journal = Journal of Immunology | volume = 152 | issue = 6 | pages = 2768–77 | date = March 1994 | doi = 10.4049/jimmunol.152.6.2768 | pmid = 7511626 | s2cid = 23491895 | doi-access = free }}
• {{cite journal | vauthors = Chalupny NJ, Kanner SB, Schieven GL, Wee SF, Gilliland LK, Aruffo A, Ledbetter JA | title = Tyrosine phosphorylation of CD19 in pre-B and mature B cells | journal = The EMBO Journal | volume = 12 | issue = 7 | pages = 2691–6 | date = July 1993 | pmid = 7687539 | pmc = 413517 | doi = 10.1002/j.1460-2075.1993.tb05930.x }}
• {{cite journal | vauthors = Rubinstein E, Benoit P, Billard M, Plaisance S, Prenant M, Uzan G, Boucheix C | title = Organization of the human CD9 gene | journal = Genomics | volume = 16 | issue = 1 | pages = 132–8 | date = April 1993 | pmid = 8486348 | doi = 10.1006/geno.1993.1150 }}
• {{cite journal | vauthors = Schmidt C, Künemund V, Wintergerst ES, Schmitz B, Schachner M | title = CD9 of mouse brain is implicated in neurite outgrowth and cell migration in vitro and is associated with the alpha 6/beta 1 integrin and the neural adhesion molecule L1 | journal = Journal of Neuroscience Research | volume = 43 | issue = 1 | pages = 12–31 | date = January 1996 | pmid = 8838570 | doi = 10.1002/jnr.490430103 | s2cid = 84774340 }}
• {{cite journal | vauthors = Sincock PM, Mayrhofer G, Ashman LK | title = Localization of the transmembrane 4 superfamily (TM4SF) member PETA-3 (CD151) in normal human tissues: comparison with CD9, CD63, and alpha5beta1 integrin | journal = The Journal of Histochemistry and Cytochemistry | volume = 45 | issue = 4 | pages = 515–25 | date = April 1997 | pmid = 9111230 | doi = 10.1177/002215549704500404 | doi-access = free }}
• {{cite journal | vauthors = Rubinstein E, Poindessous-Jazat V, Le Naour F, Billard M, Boucheix C | title = CD9, but not other tetraspans, associates with the beta1 integrin precursor | journal = European Journal of Immunology | volume = 27 | issue = 8 | pages = 1919–27 | date = August 1997 | pmid = 9295027 | doi = 10.1002/eji.1830270815 | s2cid = 42866423 }}
• Cho, J.H., Kim, E., Son, Y. et al. (2020). CD9 induces cellular senescence and aggravates atherosclerotic plaque formation. Cell Death & Differentiation https://doi.org/10.1038/s41418-020-0537-9

{{refend}}

• {{UCSC gene info|CD9}}

{{Clusters of differentiation}}

{{Membrane proteins}}