PDCD1 and cancer: The efficacies of these anti-PD-1/PD-L1 agents have been proven across various cancer types, such as melanoma (Hamid et al., 2013; Robert et al., 2015; Weber et al., 2015b), non-small-cell lung cancer (NSCLC) (Nishio et al., 2017), and Hodgkin lymphoma (Maruyama et al., 2017).