Cells were crosslinked with formaldehyde and disuccinimidyl glutarate. Cell lysates were subjected to two-step DNA fragmentation by a probe-type sonifier and a water bath sonifier, and chromatin-DNA complexes were pulled down using the specific antibody. Libraries were prepared using NEBNext Ultra II DNA Library Prep Kit for Illumina (New England BioLabs) according to the manufacturer's instructions. Briefly, ChIP DNA was end-repaired using an end prep enzyme. After adapter ligation, DNA was PCR amplified with NEB Index primers for 8-10 cycles. The purified DNA was checked for quality on Agilent TapeStation instrument with an Agilent High Sensitivity D1000 kit. The library DNA was approximately 170–500 bp in length. Libraries ware quantified using quantitative real-time PCR with the Kapa Library Quantification Kit. Diluted library DNA was subjected NextSeq sequencers (Illumina) according to the manufacturer's protocols.