CD274 and hepatocellular carcinoma: On the other hand, in hepatocellular carcinoma, FGFR4 inhibition promotes PD-L1 ubiquitin–proteasome degradation via GSK3β activation and suppresses IL-2–induced STAT5 phosphorylation to limit Treg differentiation, thereby reducing PD-L1 levels and immunosuppression and enhancing anti-PD-1 efficacy [142].