Loss and inactivation of PTEN and elevated PtdIns(3,4,5)3 and AKT activity is a common feature of T-ALL malignancy.12 In many cells PtdIns(3,4,5)P3/AKT signaling has a role to control the activity of mTORC1.48 However, we show that PTEN loss and AKT activation alone is not sufficient to activate mTORC1 in T cells. This evidence concerns the gene PTEN and acute lymphoblastic leukemia.