We reported previously that the LSC-enriched Lin-CD3+KITmid subpopulation in the Pten-null T-ALL model contains heterogeneous cells, of which 30% are MYC low, rapamycin- and JQ1 (a BRD4 inhibitor)-resistant, and relatively quiescent in terms of cell cycle (Guo et al., 2008; Schubbert et al., 2014) (Figure 1—figure supplement 1A). The gene discussed is PTEN; the disease is acute lymphoblastic leukemia.