PARP9 and systemic lupus erythematosus: Differentially methylated genes, such as MX1, IFI44L, IFIT1, IFI44, IRF5, IRF7, MHC-class III, PARP9, UHRF1-binding protein 1 (UHRF1BP1), radical S-adenosyl methionine domain containing 2 (RSAD2), phospholipid scramblase 1 (PLSCR1), ubiquitin-conjugating enzyme E2 L3 (UBE2L3), CD45, Ikaros family zinc finger 3 (IKZF3), and histone E3 ubiquitin ligase 3L (DT3XL), were identified in peripheral blood mononuclear cells (PBMCs) from SLE patients [94,95].