Indeed, the absolute numbers of lymphoid and myeloid cells per tumor volume is significantly higher in MC38 tumors before treatment and are indicative of a typical “hot” tumor microenvironment with susceptibility to PD1 ICB.41 Interestingly, after tumors are treated with αPD1 checkpoint, both tumor models exhibit increases in effector TIL populations, but only the MC38 tumor model shows decreased tumor growth. The gene discussed is PDCD1; the disease is neoplasm.