Cancer metabolism. Intercellular communication is facilitated by gap and tight junctions, but also by nanotubes, exosomes, and interleukins. Cancer cell metabolism mainly uses glucose through the Warburg effect, which increases acidosis in the tumor microenvironment (TME). Acidosis triggers several mechanisms for tumor survival. Under hypoxia conditions, the cancer cell can restart the oxidation chain (TCA cycle; Krebs cycle, ETC; electron transport chain) in several ways (e.g., reverse Warburg effect, mitochondrial transfer). Hypoxia promotes the formation of ROS, which play, depending on their concentration, a variety of roles in tumor progression (positive and negative). Created with BioRender.com (accessed on 2 January 2021).