Reduced BCMA expression on peripheral B cells associates with severe syndrome of systemic lupus erythematosus (SLE) patients (104); preferentially expressed by autoantibody producing CD180− B cells from active SLE patients (105); associates with TNF receptor-associated factors and activates NF-κB, elk-1, c-Jun N-terminal kinase, and p38 MAPK (106); receptor of a TNF homolog and implicated in SLE disease mediated by B cells (107). The gene discussed is TNFRSF17; the disease is systemic lupus erythematosus.