PIK3CA and neoplasm: Nevertheless, insulin signaling, which can activate PI3K and mTOR, can also sometimes increase glycolysis, but it is not clear how generally this occurs and whether changes to diet during fasting or ketosis are sufficient to suppress insulin signaling in a way that alters tumor glucose uptake, especially since other growth factors such as EGF and IGF1 are engaging these pathways and may not be responding to changes in food intake.