GPD2 and neoplasm: Other mechanisms on which Metformin play an action are: mammalian target of rapamycin (mTOR, crucial to tumor cell metabolism), adenosine mono-phosphate-activated protein kinase (AMPK), mitochondrial glycerophosphate dehydrogenase (mGPDH), and the nuclear factor kB (NF-kB) (Chan, 2016).