Cells were crosslinked with 1% formaldehyde for 10 min at room temperature and quenched with glycine. Nuclear lysates were sonicated to generate 200-500 bp fragments. Chromatin was precleared with Protein A or G Dynabeads at 4°C for 2 hours and incubated with antibody overnight at 4°C. Isolated chromatin was washed, eluted, reverse crosslinked and purified by standard methods. Libraries were constructed using the standard protocol. Genomic fragments were end repaired (NEBNext End Repair Module), A-tailed by adding adenosine to the 3’ ends of fragment using Klenow fragment (3’ to 5’ exo minus, New England Biolabs), and adaptors were ligatedat room temperature for 1 hr with T4 DNA ligase (New England Biolabs). Libraries were amplified with Illumina primers using the KAPA SYBR FAST qPCR Master Mix.