With the exhilarating efficacy of immunotherapy in melanoma, lung cancer, breast cancer and other malignant tumours, the ICB therapy against PD‐1 or PD‐L1 has become a clinical hot spot (Garon et al., 2015; Patnaik et al., 2015; Topalian et al., 2014). Here, PDCD1 is linked to melanoma.