TNFRSF17 is a member of the TNF-receptor family, known as tumor necrosis factor receptor superfamily member 17, also known as B cell maturation antigen (BCMA or BCM) or CD269. It is a protein encoded by TNFRSF17 gene. The receptor is expressed on the surface of B lymphocytes and plasma cells and is a marker protein of B lymphocyte maturation.The main ligands of BCMA are BAFF and APRIL. BCMA combined with BAFF could activate the classical and non-classical NF-κB and JNK signaling pathways, up-regulate the expression of anti-apoptotic protein and down-regulate the expression of pro-apoptotic protein. When BCMA binds to APRIL, the expression level of immune checkpoint is up-regulated, creating an immunosuppressed bone marrow microenvironment.