In particular, the treatment with monoclonal antibodies against the immune checkpoint molecules programmed death-ligand 1 (PD-L1) and programmed cell death protein 1 (PD-1) has improved the survival of patients with malignant tumors, including advanced melanoma, non-small cell lung cancer, and renal cell carcinoma [6,7]. Here, PDCD1 is linked to renal cell carcinoma.