CXCL9 and cancer: In combination with our results, in some cancer types, the expression of CCL5, CXCL9, and CXCL10 can function as a significant predictor in response to PD-1 blockade; and the combination of agents that can increase the expression of T-cell chemokines by tumor cells and PD-1 blockade is able to provide a new strategy to augment the efficacy of cancer immunotherapy.