In CRC, components of the tumor microenvironment such as Tregs, IL-10, TAMs, MDSCs, and associated cytokines can mediate resistance to PD1/PD-L1 blockade therapies.365 Notably, while combination therapies have been proposed as a means to circumvent resistance, the sheer number of potential combinations surpasses those subjected to clinical evaluation. The gene discussed is PDCD1; the disease is colorectal carcinoma.