In in vitro and in vivo xenograft models of lung cancer and melanoma cells, CAFs produce IGF1/2, CXCL12 and β-hydroxybutyrate and increase the level of ROS postradiation, which enhances protein phosphatase 2A (PP2A) activity, resulting in repressing mTOR activation and increasing autophagy in cancer cells postradiation. Here, CXCL12 is linked to cancer.