AKT1 and cancer: The phosphorylation of Akt-mediated phosphoenolpyruvate carboxykinase 1 (PCK1) at S90 can reduce its gluconeogenic activity and use GTP as a phosphate donor to phosphorylate Insig1/2 in the endoplasmic reticulum, which activates SREBP signaling for lipid synthesis in cancer (103).