Six studies reported the rate of positive PD-L1 expression, and three of them compared the difference in efficacy of PD-1 inhibitors in NPC patients with positive versus negative PD-L1 expression [15, 16, 25], showing that anti-PD-1 therapy could benefit regardless of PD-L1 expression status, and the benefit was more pronounced in those with positive PD-L1 expression (ORR, 31% vs. 21%). Here, CD274 is linked to nasopharyngeal carcinoma.