Recently, Kobayashi et al. revealed that the incidence rate of ipilimumab-induced hypopituitarism was 24% and that of nivolumab and pembrolizumab (anti-PD-1 mAb)-induced hypopituitarism was 6% in patients with malignant melanoma or non-small cell lung carcinoma (NSCLC) [19]. Here, PDCD1 is linked to melanoma.