PDCD1 and colorectal carcinoma: The PD-L1 expression level appeared to be a persuasive marker because PD-L1-positive lesions were more vulnerable to PD-1 inhibition therapy than PD-L1-negative lesions, yet clinical survival data did not show a significant relationship.414–417 The predictive role of PD-L1 expression in CRC is considered to be limited because in pMMR CRC, no obvious trend was observed between PD-L1 expression levels and drug efficacy.382,387