Tumor necrosis factor receptor type II (TNFR2) is expressed both by some cancer cells and by tumor-infiltrating immunosuppressive CD4(+)FoxP3(+) regulatory T cells (T-regs). TNFR2 stimulates the activation and proliferation of T-regs, a major checkpoint of antitumor immune responses, and promotes cancer cell survival and tumor growth. In this issue of Science Signaling, Torrey et al. found that dominant antagonistic antibodies against human TNFR2 may be a potential therapy for ovarian cancer patients by simultaneously suppressing T-reg activity and inducing the death of the cancer cells.