CUL4B-DDB1 inhibits the activation of the mTORC1 signaling pathway by interacting with Raptor and promoting the polyubiquitination of its K48 linkage, an effect that leads to the down-regulation of the expression of genes related to adipogenesis, oxidation, lipid uptake, and secretion (such as, SREBP1, PPARα, CD36, APOE), which attenuates hepatic steatosis in NAFLD (53). Here, CUL4B is linked to metabolic dysfunction-associated steatotic liver disease.