MTOR and cancer: Several approaches have been put forth to combat hypoxia in cancer, including the use of hypoxia-activated prodrugs (HAPs), suppression of HIF signaling, metabolic intervention, as well as downstream targeting of crucial hypoxic pathways, such as the mTOR and unfolded protein response (UPR) pathways; others are still in the conceptual design phase, such as siRNA-mediated gene treatments and recombinant anaerobic bacteria [149].