Laminin alpha-5 receptor. May mediate intracellular signaling. Wide tissue distribution (highest in the pancreas and very low in brain). Closely associated with the basal layer of cells in epithelia and the endothelium of blood vessel walls. Is under developmental control in liver and may also be regulated during differentiation in other tissues. Up-regulated following malignant transformation in some cell types. Epinephrine-stimulated phosphorylation of Ser-621 by PKA enhances adhesion to laminin. BCAM is responsible for the Lutheran blood group system (LU) [MIM:111200]. Lutheran is a complex blood group system consisting of 19 antigens. Antigens Lu(a) and Lu(b) are defined by a polymorphism at position 77: Lu(a) has His-77 and Lu(b) has Arg-77. Inactivating variants in BCAM are responsible for the recessive Lutheran null phenotype Lu(a-b-) of the Lutheran blood group [MIM:247420]. Autosomal recessive inheritance of the Lutheran null blood group phenotype is extremely rare. There is no obvious associated clinical or hematologic pathology, and all patients have been identified through identification of anti-Lu3 antibodies in their serum. Blood group antigen gene mutation database