PDCD1 and neoplasm: CD4+ depletion on the other hand did not affect the anti-PD-1-antibody efficacy (TGI 46%), while CD25+  and TAM depletion enhanced anti-PD-1 antibody efficacy (TGI 94% and TGI 76%, respectively), suggesting that, like the MC38 model, an immune suppressive TME mediated via Treg and TAM counters the anti-PD-1 MOA in CT-26 tumor.