When comparing tumors with different grades (G1/G2 vs. G3/G4), a statistically significant elevation in urine PD-L1 levels was found in more differentiated tumors (73.62 vs. 6.13 pg/mL, p = 0.033), although it needs to be mentioned that G3/G4 tumors comprised only 6.1% of the RCC cohort (Figure 4A). The gene discussed is CD274; the disease is renal cell carcinoma.