Cells were crosslinked in 1% formaldehyde for 10 min and then quenched in 100mM glycine. Nuclear enrichment was performed followed by sonication (Bioruptor plus, Diagenode). Chromatin was immunoprecipitated over night using specific antibodies. Beads were washed six times in RIPA buffer and eluted from beads using SDS buffer. After RNase and proteinase K treatment, DNA was purified by phenol/chloroform extraction. Libraries were prepared using the Thruplex kit (Illumina) according to the manufacturer's instructions.