For the first-line treatment of metastatic kidney cancer, the CheckMate 214 study found that the combination of the PD1 antibody nabumab and the CTLA-4 antibody epitumumab was significantly superior to the targeted drug sunitinib in terms of overall survival for intermediate- and high-risk metastatic kidney cancer in International Metastatic Renal-Cell Carcinoma Database Consortium (IMDC) (Motzer et al., 2018). Here, PDCD1 is linked to renal cell carcinoma.