IDO1 and nonpapillary renal cell carcinoma: Classical immunosuppressive cytokines, including vascular endothelial growth factor (VEGF), transforming growth factor-β (TGF-β), indoleamine 2,3-dioxygenase (IDO), and interleukin (IL)-10, and indicators of effector T-cell killing activity, including GZMB and cytolytic activity, did not change during ccRCC progression (Figure 6).