5 million cells were formaldehyde-fixed at 1% for 8 minutes, sonicated 14x in BioRuptor Pico and the ChIP against H3K27ac (ab4729, Abcam) was done with the iDeal ChIP-seq kit for histones as per the manufacturer's protocol (Diagenode) Libraries were prepared using the TruSeq ChIP Sample Prep kit and we performed paired-end sequencing with the NextSeq 500/550 High Output Kit v2.5 (150 Cycles) (Illumina)