IGF1 and cancer: Metformin directly inhibits the growth of insulin-induced malignant tumors in an AMPK/mTOR dependent manner and can affect tumorigenesis by regulating IGF.[72] Metformin reduces the binding of ligand IGF to the receptor IGF-R through the AMPK/mTOR pathway and indirectly downregulates the insulin signaling pathway in tumors, thereby inhibiting tumor growth.[55]