For example, erdafitinib can reduce PD-L1 expression on tumor cells and enhance T cell activation in certain models, thereby improving the efficacy of anti-PD-1 antibodies; conversely, in FGFR3-activated bladder cancer models, FGFR3 inhibition can upregulate PD-L1 levels through modulation of the E3 ubiquitin ligase NEDD4, paradoxically attenuating immune responses [138,139,337]. The gene discussed is FGFR3; the disease is urinary bladder cancer.