NSUN2 and systemic lupus erythematosus: m5C levels and NSUN2 expression are decreased in the CD4+ T cells of systemic lupus erythematosus (SLE) patients, and hypermethylated m5C in SLE is closely associated with the immune- and inflammation-related pathways, including the immune system, cytokine signaling, and interferon (IFN) signaling.318 In the CD4+ T cells of SLE patients, ac4C modification in mRNAs is highly conserved and enriched in mRNA CDS regions and participates in critical immune and inflammatory signaling in SLE pathogenesis.319