CD38 and systemic lupus erythematosus: The pro-apoptotic effect of CD38 and TRPM2 expression in Ly6Chi monocytes is particularly harmful in the pristane-induced model of lupus in which PECs lack highly phagocytic resident peritoneal macrophages (Tim4+ macs), and have low numbers of anti-inflammatory elicited macrophages (Tim4−CD138+Marco+ macs), which have increased phagocytic capacity for apoptotic cell clearance compared to Tim4+ macs (81).