TGFB1 and metabolic dysfunction-associated steatohepatitis: For example, in the liver, hepatic stellate cells are activated by stimuli such as TGF-β1 and transdifferentiate into myofibroblasts, which promote the production of extracellular matrix components such as collagen and induce liver fibrosis in diseases such as nonalcoholic steatohepatitis [32].