To identify the “time-lapse” TF networks during B lineage commitment, we established multipotent progenitors harboring a tamoxifen-inducible form of Id3, an in vitro system where virtually all cells became B cells within 6 days by simply withdrawing 4-OHT. In this study, epigenomic analysis at multiple time points was performed using the culture system. Overall design: Time-course epigenomic profiles of multipotent iLS cells toward B committed cells were analyzed by deep sequencing using Illumina Hiseq platform.