Figure 1. Targeted depletion of regulatory T cells, exhausted helper T cells and myeloid-derived suppressor cells may restore effete antitumor T-cell function. (A) The accumulation of exhausted effector helper T cells, immunosuppressive GARP+CTLA4+ regulatory T cells (Tregs) and myeloid-derived suppressor cells (MDSCs) reduces the antitumor effects of TH1 cells and cytotoxic T lymphocytes (CTLs) by inhibiting granzyme B production and interferon γ (IFNγ) secretion. (B) The restoration of effector T-cell proliferation and granzyme B production (but not IFNγ secretion) by the combined removal of all these immunosuppressive cells may restore antitumor TH1 and CTL responses.