Contributes to phagocytic removal of apoptotic cells in many tissues. Specific ligand for the alpha-v/beta-3 and alpha-v/beta-5 receptors. Also binds to phosphatidylserine-enriched cell surfaces in a receptor-independent manner. Zona pellucida-binding protein which may play a role in gamete interaction (By similarity). Plays an important role in the maintenance of intestinal epithelial homeostasis and the promotion of mucosal healing. Promotes VEGF-dependent neovascularization. Located in the acrosomal region of zona-pellucida bound sperm. Mammary epithelial cell surfaces and spermatozoan. Isoform 2 is present in brain, heart, kidney and spleen and at low levels in lung, liver, small intestine and testis. Isoform 1 and isoform 2 are detectable in mammary tissue from non-pregnant animals, with isoform 2 being predominant. Levels of isoform 1 increase during gestation and lactation while levels of isoform 2 decrease. Isoform 1 is induced by insulin, prolactin and hydrocortisone in mammary epithelial cells. Expression of isoform 2 is repressed by the same treatment. The F5/8 type C 2 domain mediates high-affinity binding to phosphatidylserine-containing membranes. N-glycosylated. Isoform 1 also exists in both an O-glycosylated and a non-O-glycosylated form.