DNA methylation is often inversely proportional to the transcriptional activity of genes, and PARP9 and IFI44L showed marked hypomethylation in a variety of immune cells in SLE patients (Ulff-Møller et al., 2018), including CD4+ T cells, monocytes, granulocytes, and B cells. Here, IFI44L is linked to systemic lupus erythematosus.