The findings might suggest that in patients with leukemia: (1) TIGIT is expressed by at Treg subset that is FoxP3+Helios+ and expresses IL-10; (2) CTLA-4 and CD39 are expressed by tTreg and/or pTreg subsets that are FoxP3+Helios− and express IL-10; (3) TIM-3 is expressed by a tTreg and/or pTreg subset that is FoxP3+Helios− and expresses both IL-10 and TGF-β; (4) TNFR2 is expressed by a FoxP3−Helios− pTreg subset that expresses IL-10 and TGF-β. The gene discussed is HAVCR2; the disease is leukemia.