...we investigated immune evasion mechanisms and found that a high fraction of intratumoral or peritumoral PD-1 positive cells was significantly associated with treatment response (p = 0.008, p = 0.002, respectively...In the present study, we showed that a high fraction of intratumoral and peritumoral PD-1 positive cells correlated with treatment response, whereas no association between PD-L1 and response was observed.