Background: Colorectal carcinoma is the most common gastrointestinal malignancy, and the incidence is increase every year. More than 90% of colorectal malignancies are adenocarcinomas, which are malignancies of epithelial origin with glandular or mucinous differentiation. PD-L1 is one of the immune checkpoints that is currently being widely studied because of its important role in the process o…