EPAS1 and neoplasm: Moreover, lactate probably stabilizes HIF-2α inside TAMs by activating the mammalian target of rapamycin complex 1 (mTORC1), which acts as a nutrient/energy/redox sensor and controls protein synthesis, leading to inhibition of the expression of transcription factor EB in xenograft mouse tumor models [26] and, subsequently, to the decreased expression of Atp6v0d2, which encodes the macrophage-specific ATPase subunit involved in HIF-2α degradation.