PDCD1 and neoplasm: In a phase II clinical trial that was conducted to evaluate the sensitivity to anti-PD-1 therapy in metastatic triple-negative breast cancer, the performance of short-term cisplatin and doxorubicin treatment followed by nivolumab demonstrated significant improvements in patient outcomes; the ORR of cisplatin was 23% and that of doxorubicin was 35%, while the overall ORR was 20%, supporting that short-term cisplatin and doxorubicin treatment before nivolumab can improve the tumor microenvironment and enhance the sensitivity to anti-PD-1 therapy (29).