STK11 and neoplasm: Mammalian target of rapamycin complex 1 (mTORC1) is inhibited by the LKB1/AMPK pathway, via tuberculous sclerosis complex 1 and 2 (TSC1 and TSC2) activation, which induces protein synthesis disruption and inhibition of tumor cell proliferation.[50] Therefore, research on the mechanism of metformin has focused on the LKB1-AMPK-mammalian target of rapamycin (mTOR) pathway.