ULK1 and neoplasm: Since mTORC1 is a vital negative regulator of autophagy32, we checked autophagy-related markers and found the reduced LC3 II/I ratio, while elevated level of phosphorylation of ULK1 in TET2-deficient tumor cells, both of which can be rescued by rapamycin treatment (Fig. 1f), indicating that TET2 is also required for activation of autophagy.