PDCD1 and renal cell carcinoma: In 2015, nivolumab (anti PD-1) became the first US Food and Drug Administration (FDA)-approved ICB for advanced RCC, after showing a benefit in OS over everolimus (median OS, 25.8 vs. 19.7 months; hazard ratio (HR), 0.73; 95% confidence interval (CI), 0.62–0.85) in previously treated RCC in the CheckMate-025 phase III trial [17,18].