CTLA4 and neoplasm: While inhibition of cytotoxic T lymphocyte activation-4 (CTLA-4) and programmed death-1 (PD-1) on T cells are central to reversing immunosuppression in tumors, tumor-associated myeloid cells such as myeloid-derived suppressor cells, tumor-associated macrophages, and DCs are also involved in suppressing antitumor immunity.