IL‐38, the most recently characterized member of the IL‐1 family cytokines, is abundantly expressed in various tissues and cells following stimulation with rhinovirus, inflammatory cytokines, bacteria, Toll‐like receptor (TLR) agonists or other pathogens, although IL‐38 expression in CD4+CD25+Tregs has been unclear.31, 32, 33 There is growing interest in investigating the regulatory pathway of IL‐38 in the pathogenesis of inflammatory and autoimmune disorders. The gene discussed is CD4; the disease is autoimmune disease.