SMAD4 and hepatocellular carcinoma: USP10 can directly bind to Smad4 and act on the Lys-48-linked polyubiquitin chain on Smad4 to stabilize it; USP10 regulates the abundance and function of Smad4 protein through deubiquitination and activates the TGF-β pathway to further promote the migration of hepatoma cells (87).