PTEN and acute lymphoblastic leukemia: To address if HIF1α expression in T-ALL cells is controlled by mTORC1 we switched to experiments with PTEN−/− T-ALL cell lines.29Figure 3e shows that the murine PTEN−/− T-ALL cell lines, F04 and F15, had high levels of mTORC1 activity, as judged by the rapamycin sensitive phosphorylation of S6K T389, and expressed HIF1α in hypoxia and normoxia (Figure 3f).