MTOR and Alzheimer disease: Trem2 fulfills microglial ATP requirements in AD by upregulating mammalian target of rapamycin (mTOR) signaling through upstream activators, such the serine/threonine-protein kinase B (Akt), pyruvate dehydrogenase kinase-1 (PDK1), and phosphatidylinositol 3-kinase (PI3K), which are recruited by the Trem2-associated signaling subunits DAP10 and DAP12 (Peng et al., 2010).