FGF21 and fatty liver disease: Yano et al. demonstrated that fibroblast growth factor 21 (FGF21), an endocrine growth factor, induced the phosphorylation of AMPK at Thr172 and Raptor at ser792 and suppressed mTOR at ser2448, which downregulated mTORC1 signaling and contributed to improved liver steatosis in HFD-fed mice [136].