背景资料:CD51 represents the integrin alphaV chain that associates with integrin beta3 (CD61) to form the CD51/CD61 vitronectin receptor on endothelial cells, certain activated leukocytes, NK cells, macrophages, neutrophils, and platelets. CD51 is the most promiscuous integrin alpha subunit as it can form heterodimers with the beta1 (CD29), beta3 (CD61), beta5, beta6 and beta8 subunits in various tissues. CD51/CD61 acts as an activation-independent receptor for platelet attachment and spreading on vitronectin and other RGD-containing proteins including matrix components. It also mediates leukocyte-endothelial cell adhesion via interaction with CD31.