Cells were crosslinked with a 1% formaldehyde final concentration, then resuspended and digested with Micrococcal nuclease. Digested DNA fragments between 150-900 base pairs were sonicated using a Branson 250 sonicator, with pulse amplitude of 32%, pulsing for 0.7 seconds with 1.3 seconds in between for a total pulse period of 5 minutes on ice. Chromatin was diluted 10x and incubated with 3-5 ug of antibodies overnight at 4°C with agitation. Histone complexes were precipitated by Protein G Magnetic Beads, then washed 3x with a low salt solution and 1x with a high salt solution. Chromatin was eluted and cross-linking was reversed with 5M NaCl and then treated with Proteinase K. DNA was purified using DNA wash Buffer and then eluted with Elution Buffer. ChIP libraries were built by starting from ChIP DNA (5ng), followed by end preparation, adaptor ligation and amplification, indexed with Dual Index 7 Primers and 5 Primers from Multiplex Oligos (CST# 47538) compatible with Illumina. AMPure XP and SPRI Select beads were used to clean up amplified DNA.