Cellular localization of PD-L1 expression in mismatch-repair-deficient and proficient colorectal carcinomas.

Blockade of the interaction between PD-1 and its ligands PD-L1 has shown clinical efficacy across several tumor types, especially in mismatch-repair-deficient colorectal carcinoma. The aim of this study was to examine the pattern and cellular localization of PD-L1 expression in the different molecular subtypes of mismatch-repair-deficient colorectal cancers vs. their mismatch-repair-proficient counterparts.