For ChIP-Seq data of histone markers, crosslinked chromatin was isolated from freshly cultured cells and sonicated into small fragments for immunoprecipitation with antibodies against each histone modification marker, including anti-H3K4me3 (Abcam, ab8580; Active Motif, 39915), anti-H3K9ac (Abcam, ab4441; Active Motif, 39917), anti-H3K9me3 (Abcam, ab8898; Active Motif, 39161), anti-H3K27ac (Abcam, ab4729; Active Motif, 39133), and anti-H3K27me3 (Cell Signaling, C36B11; Active Motif, 39155) antibodies. ChIP DNA was used for the library preparation using the NEBNext ChIP-Seq Library Prep kit (NEB) following manufacturer's protocol and sequenced using the HiSeq 2000 (Illumina).