CXCL12 and cancer: It is likely this response is at least in part related to CAF-secreted IGF1/2, CXCL12, and β-hydroxybutyrate, leading to increased reactive oxygen species (ROS), enhancing protein phosphatase 2A (PP2A) activity, repressing mTOR activation, and ultimately resulting in autophagy in cancer cells after irradiation [118,119].