Besides, in addition to promoting the survival and differentiation of autoreactive B cells in mature stage (139), BAFF can also facilitate the proliferation and antibody-secretion of immature-transitional B cells (180), indirectly promote the expansion of Th17 cells in RA and directly regulate the accumulation and cytokine-secretion of Tfh cells in SLE (181, 182), which is likely to be also involved in the pathogenesis of MG and NMO and deserves to be investigated. The gene discussed is TNFSF13B; the disease is neuromyelitis optica.