Notably, both HIF-2α and c-Maf were recently identified to be essential for the effector program and suppressive functions of Treg cells, although the severity of autoimmune disease in TfR1 cKO mice was much greater than that in mice with either c-Maf-deficient29,30 or HIF-2α-deficient Tregs74. The gene discussed is TFRC; the disease is autoimmune disease.