KIT and leukemia: To profile chromatin landscape, we performed the assay for transposase-accessible chromatin (ATAC-seq)27 on in vivo-derived bulk leukaemias from each cell of origin, and compared this with published ATAC-seq data on normal cell types including LSK (Lin− Sca-1+ c-Kit+, includes ST-HSC and MPP), CMP and GMP by Lara-Astiaso et al.25 We found that ATAC-seq peaks are most abundant in intergenic and intronic regions, followed by promoter regions (Fig. 4a), suggesting that ATAC-seq offers distinct regulatory information than what can be gained from transcriptional signatures alone.