Tumor necrosis factor receptor superfamily, member 17 (TNFRSF17), also known as B cell maturation antigen (BCMA) or CD269 antigen, is a member of the TNF-receptor superfamily. This receptor is preferentially expressed in mature B lymphocytes, and may be important for B cell development and autoimmune response. This receptor has been shown to specifically bind to the tumor necrosis factor (ligand) superfamily, member 13b (TNFSF13BBAFF), and to lead to NF-kappaB and MAPK8/JNK activation. TNFRSF17/BCMA/CD269 also binds to various TRAF family members, and thus may transduce signals for cell survival and proliferation. TNFRSF17/BCMA/CD269 is a receptor for TALL-1 and BCMA activates NF-kappaB through a TRAF5-, TRAF6-, NIK-, and IKK-dependent pathway. The identification of TNFRSF17 as a NF-kappaB-activating receptor for TALL-1 suggests molecular targets for drug development against certain immunodeficient or autoimmune diseases. TNFRSF17/BCMA is a target of donor B-cell immunity in patients with myeloma who respond to DLI. Antibody responses to cell-surface BCMA may contribute directly to tumor rejection in vivo.