PDCD1 and neoplasm: Previous studies have investigated the potential of targeting the highly expressed methionine transporter SLC43A2, the m6A‐specific binding protein YTHDF1, and the lysine methyltransferase SUV39H1 in tumor cells.[6, 29, 30] Our results also suggest the feasibility of a combination therapy involving blockade of PD‐1 and inhibition of PCSK9, a novel effector of methionine catabolism and a key orchestrator of cholesterol homeostasis highly expressed in tumor cells, for MSS CRC.