CD4 and systemic lupus erythematosus: DNA hypomethylation in IFN-associated genes, such as poly (ADP-ribose) polymerase family member 9 (PARP9), IFN-induced transmembrane protein 1 (IFITM1), and IFI44L was demonstrated in CD4+ T cells, B cells, granulocytes, and monocytes from SLE patients [93].