TNFRSF17 (B-cell maturation antigen/BCMA) is a TNF receptor superfamily member that serves as a critical survival receptor for mature B lymphocytes and plasma cells. The receptor binds ligands TNFSF13B/BLyS/BAFF and TNFSF13/APRIL, promoting B-cell survival through NF-κB and JNK signaling pathway activation [UniProt function]. BCMA plays a central role in humoral immunity regulation and adaptive immune responses through its expression on mature B cells and plasma cells. Clinically, TNFRSF17 has emerged as a major therapeutic target in multiple myeloma (MM), a malignancy of plasma cells that express BCMA at high levels 1. Multiple BCMA-targeted immunotherapies have demonstrated remarkable efficacy, including bispecific T-cell engagers (teclistamab), chimeric antigen receptor T-cell (CAR-T) therapies (bb2121), and antibody-drug conjugates 123. Teclistamab achieved a 63.0% overall response rate in heavily pretreated patients, with durable responses (median 18.4 months) 3. However, antigen escape through TNFRSF17 loss represents an important resistance mechanism, with biallelic deletions and mutations at the TNFRSF17 locus driving relapse in some patients 4. Beyond myeloma, BCMA-targeting CAR-T cell therapy shows promise in systemic lupus erythematosus with lupus nephritis, achieving medication-free remission and autoantibody depletion 5.