PDCD1 and hereditary clear cell renal cell carcinoma: Given VTP’s enhancement of antitumor immune responses, O’Shaughnessy et al. evaluated whether VTP could potentiate the efficacy of the programmed cell death protein-1 (PD-1) and the programmed death protein ligand-1 (PD-L1) pathway inhibition using an orthotopic murine model of renal cell carcinoma that develops lung metastases [35].