Basal cell adhesion molecule (BCAM, CD239) is an immunoglobulin superfamily protein that arises from alternate splicing of the Lutheran blood group molecule (Lu). The ECD of human BCAM contains two Ig-like V-type domains and three Ig-like C2-type domains. It shares 73% aa sequence identity with the ECDs of mouse and rat BCAM. BCAM is widely expressed in epithelial and endothelial tissues including in the vasculature, kidney glomerulus, small intestine, colon, hair follicle outer root sheath, and basal keratinocytes of the skin during inflammation. BCAM is also expressed on vascular and visceral smooth muscle cells and at the neuromuscular junction of skeletal muscle. BCAM is upregulated on carcinomas, particularly ovarian, sarcomas, astrocytomas, and melanomas. It may mediate intracellular signaling. It cooperates with Integrins β1 and αVβ3 as an adhesion receptor for Laminins which contain the α5 chain. The Lutheran isoform is aberrantly phosphorylated in erythroid disorders and can enhance Lamininmediated adhesion of erythrocytes to vascular endothelial cells.