CD8A and cancer: In particular, we aim to assess the influence of the PIs on MAPK and SMAD pathway protein expression and phosphorylation via immunoblotting, determine the protein‐receptor binding constant for the most biologically active PI via microscale thermophoresis (MST), assess the effects of our PIs on A498, 786‐O, Caki‐1 and Caki‐2 cancer cell lines via MTT assays, clonogenic assays, cytometric measurements and RNA‐seq—and finally evaluate the influence of PIs on CD4+/CD8+ T‐cell exhaustion with the use of cytokine panels and immunoblotting.