RSAD2 and systemic lupus erythematosus: Type I IFN-mediated viral inhibitory protein, widely involved in antiviral activity. Some studies have found that the expression of methylated RSAD2 in naive CD4+ T cells of SLE patients is significantly increased, and the methylation of the RSAD2 gene CpG site is related to the production of SLE-related autoantibodies (33).