SDC1 and infection: For example, the pro-survival factor Tnfsf13b (encoding for the B cell survival factor, BAFF) was abundantly expressed upregulated by homeostatic microglia upon infection, whereas the expression of its cognate receptor Tnfrsf17 (or B cell maturation antigen, BCMA) was highly expressed in Cd138+ plasma cells from infected animals (Fig. 6B and C).