Extracellular signals activate two major signaling cascades controlled by the activation of PI3K and Ras. PI3K and Ras regulate Akt and ERK, which in turn induce changes in intermediate metabolism to promote anabolic processes. In addition, they also induce the activation of mTORC1, thus further supporting the rewiring of cellular metabolism towards anabolic processes. Through various mechanisms Akt, ERK and mTORC1 stimulate mRNA translation, aerobic glycolysis, glutamine anaplerosis, lipid synthesis, the pentose phosphate and pyrimidine synthesis, thus producing the major components necessary for cell growth and proliferation.