IGF2 and cancer: Several secreted factors were identified, including various cytokines such as IGF1, IGF2, and CXCL12, all of which promoted survival of A375M melanoma and A549 lung cancer cells after radiation.226 Further, injection of CAFs at the site of tumors previously eradicated by radiation accelerated the subsequent development of tumor recurrence, which was abrogated by IGF2 knockout or 3‐MA treatment.226 This finding highlights the importance of this cytokine produced by CAFs under autophagy for cancer cell survival.