ChIPseq and ChIP-qPCR were performed as described without modifications (Pavri et al., 2010). In short, 20x10^6 cells were crosslinked with 1% HCHO for 10 min at 37 degree. After quenching with 0,125 M glycine, cells were sonicated with the Diagenode Bioruptor sonication machine. After chromatin-immunprecipitation, samples were end-repaired with the Epicenter End-Repair Kit. After A-tailing the samples with Klenow (exo-) enzyme, NEXTflex adapters were ligated to the samples and then purified with AMPure XP beads. PCR amplification of the libraries was performed with the Phusion-HF enzyme and the NEXTflex primer mix.