IL6 and acute lymphoblastic leukemia: Focusing our attention on MDSCs for their crucial ability to impair anti-tumor immune responses, we have reported that the Notch/IL-6 axis inside tumor T-cells is necessary but not sufficient for the in trans induction of functional MDSCs in the TME of our murine model of Notch-dependent T-ALL, as well as in human PBMCs [40].