CTLA4 and neoplasm: Also, chimeric antigen receptor (CAR) T cell therapy and immune checkpoint inhibitors targeting PD-1, PD-L1, or CTLA-4 have been adopted to re-invigorate T cell response in the TME via the depletion of tumor-associated macrophages (TAMs) and repolarization of immunosuppressive M2-like TAMs into anti-tumor M1-like TAM.