Of the 300 MLL-AF4 specific enhancers in ATAC cluster 3, 124 (41%) were highly enriched for H3K27ac signal compared to other ALL samples (Supplementary Fig. 3g; i.e., are found in H3K27ac cluster 4, Supplementary Fig. 2c). The gene discussed is AFF1; the disease is acute lymphoblastic leukemia.