Chromatin immunoprecipitation (ChIP) experiments were performed per standard protocols (Millipore, Billerica, MA) with minor modifications. Briefly, 10M cells were crosslinked with 1% formaldehyde for 10 min at 37 °C. This reaction was subsequently quenched with 0.125M glycine. All library prep and sequencing were 75bp single end on Illuminia Nextseq 500