And anti-PD-1 antibody, nivolumab and pembrolizumab, have shown impressive anti-tumor responses in diverse malignancies, such as melanoma, non-small cell lung cancer, head and neck squamous cell carcinoma, and metastatic urothelial carcinoma (Brahmer et al., 2015; Robert et al., 2015; Ferris et al., 2016; Sharma et al., 2017). The gene discussed is PDCD1; the disease is melanoma.