For ChIP-seq, cells were fixed in 1% formaldehyde for 10 min at RT, and followed by glycine for 5 mins. Chromatin was sonicated to 200-500 bp, and immunoprecipitated with antibodies. Anti-mouse, rabbit IgG Dynabeads (Invitrogen) or StAv beads (Invitrogen) were added and incubated at 4°C. After washing the beads, beads-bound chromatin was tagemented by ChIPmentation strategy. Chromatin was eluted by reverse crosslink buffer at 65 ℃ for 12 hrs and purified with Monarch DNA Cleanup Columns. The libraries were prepared by using the Illumina Nextera DNA Library Prep Kit, and size-selected to 200-500 bp using SPRIselect beads.