Figure 1.

Regulation of cell metabolism by proto-oncogenes and tumour suppressors. The diagram depicts growth factor receptor activation and the cascade of events that results in nutrient uptake for biomass accumulation, energy and reductive power production. The PI3K and RAS-RAF-MEK pathways are shown signalling downstream, resulting in mTOR activation and transcriptional responses, such as the path towards Myc activation. Proto-oncogenes are highlighted in green, whereas tumour suppressors are in red. Note that the mitochondrion is a key respiratory and biosynthetic organelle, from which intermediates provide the building blocks for protein, nucleic acid and lipid synthesis. The KEAP1-NRF2 pathway is shown to be activated by KEAP1 inactivation by ROS, which is a key metabolic by-product. The overarching use of oxygen is depicted with the generation of heat and ROS.