•Block the binding of TNF to human TNFR2 and hamper TNFR2 signaling activation•Inhibit TNF-induced expansion of human Tregs (in vitro assay)•Induce the death of Tregs, especially those isolated from ovarian cancer tissue (in vitro assay)•Induce the death of TNFR2-expressing OVCAR3 tumor cells (in vitro assay). Here, TNFRSF1B is linked to ovarian carcinoma.