PDCD1 and colorectal carcinoma: Furthermore, both PCSK9 inhibition and dietary methionine restriction (DMR) potentiate PD‐1 blockade therapy and foster the infiltration of CD8+ T cells in Colon 26 tumor‐bearing mice—a proficient mismatch repair (pMMR)/microsatellite stable (MSS) CRC model that exhibits limited response to anti‐PD‐1 therapy.