•Reduces the expression of Foxp3 and inhibit the suppressive function of Tregs at low doses (in vitro assay)•Reduces the proportions of TNFR2+ Tregs in the blood and bone marrow of acute myeloid leukemia (AML) patients in combination with azacitidine (in vivo assay). Here, TNFRSF1B is linked to acute myeloid leukemia.