CD274 and cancer: The histologically non-well-differentiated-type (i.e., the moderately and poorly differentiated types) and tumors in the 1st portion of the duodenum were more frequently identified in the late stages (stages III–IV) (P = 0.006 and P = 0.003) in association with PD-L1 expression in cancer cells (P < 0.0001 and P = 0.02) and immune cells (P = 0.001 and P = 0.09), respectively.