KEAP1 and hepatocellular carcinoma: Furthermore, USP15 deubiquitinates and stabilizes kelch like ECH associated protein 1 (KEAP1) to degradate nuclear factor erythroid 2-related factor 2 (NRF2), which is enhanced by xanthine oxidoreductase, thereby leading to the accumulation of reactive oxygen species and changes in the oxidative environment, ultimately inducing cell apoptosis and suppressing the propagation of hepatocellular carcinoma [79].