Knoechel et al. demonstrated that T-cell acute lymphoblastic leukemia (T-ALL) can acquire resistance to γ-secretase inhibitors (GSIs) via a fully reversible epigenetic mechanism, and GSIs and the BRD4 inhibitor JQ1 have synergistic effects on GSI-tolerant “persister” cells [41]. Here, BRD4 is linked to T-cell acute lymphoblastic leukemia.