In addition, in a pooled analysis, among the melanoma patients continuing the application of PD-1 inhibitors, 19% (95/500) patients had a more than 30% decrease of tumor burden, and patients continuing the PD-1 inhibitors had an improved OS than those discontinuing the immunotherapy (Long et al., 2017; Beaver et al., 2018). Here, PDCD1 is linked to melanoma.