TNFSF13B and systemic lupus erythematosus: We found increased expression of Tnfsf13b, encoding the B/plasma cell survival factor BAFF, in lupus-enriched TrMac subsets (MNP1.3, 1.4, and 1.5) in MRL-Lpr kidneys compared with MRL-MpJ, with little Tnfsf13b expression in MoMac subsets (Figure 7A and Supplemental Figure 4A).