MTOR and cancer: Whereas in a state of authentic nutrient and oxygen depletion (Figure 2A) mTOR signaling is physiologically downregulated by AMPK, the ROS-mediated pseudohypoxic state cancer cells provoke in surrounding fibroblasts (Figure 2B) results in simultaneous and persistent activation of autophagy-promoting AMPK signaling, on the one hand, and elevated mTOR signaling, on the other hand - an unphysiological condition, leading to macromolecule abundance and catabolism.