We observed a peak of H3K27me3 at the promoter of PROM1 in both RCH-ACV and ML-2 cells (Fig. 5b and Supplementary Fig. 4b), colocalizing with EZH2 in RCH-ACV cells (Fig. 5b and Supplementary Fig. 4c), indicating that this may be a common mechanism to repress PROM1 in CD133− AML and ALL cells. The gene discussed is PROM1; the disease is acute myeloid leukemia.