Purpose: The goals of this study are to elucidate the underlying mechanism for the regulation of HSC divisions. Methods: One hundred thousand cells of subfractions within the HSC fraction were sorted. These cells were subjected to ATAC-sequence by using 10X Genomics Chromium Next GEM Single Cell ATAC Reagent Kits v1.1. The sequence reads that passed quality filters were analyzed by FASTX-toolkit. Overall design: EPCR+ or +++ fraction within the HSC fraction (CD150+ CD48- EPCR+ Lineage-) were sorted, and subsequently ATAC peaks were generated by deep sequencing using Hi-seq.