Five different meta‐analysis have been reported to investigate the efficacy of immune checkpoint inhibitors according to the sex of cancer patients.11, 13, 32, 33, 34 In the previous meta‐analysis conducted by Botticelli and colleagues,34 there was no significant improvement of overall survival in male cancer patients treated with anti‐PD‐1 or anti‐CTLA‐4 antibodies. Here, PDCD1 is linked to cancer.