XL-13m displays 5-fold selectivity for ENL YEATS (IC50 = 0.56 μM) over AF9 YEATS (IC50 = 2.5 μM).In acute leukemia cells, XL-13m reduced ENL chromatin occupancy anddownregulated critical leukemogenic genes including HOXA10, MYB, MYC,and MEIS1. The gene discussed is MLLT1; the disease is acute leukemia.