The expression of TLR7 mRNA in PBMCs and monocytes of MS was damaged (TLR9 signal damage was not observed), which inhibited the secretion of IL-6 and B cell activating factor (BAFF) (76, 77) that regulates the survival, differentiation and class switching of B cells. The gene discussed is TNFSF13B; the disease is myeloid sarcoma.