Histone modifications were immunoprecipitated with the respective antibody (Lee et al., 2006, Jerkovic et al., 2017) and trascription factor ChIPs were performed with the iDeal ChIP-seq kit for Transcription Factors (Cat. No. C01010055) according to guidelines. We sheared chromatin using Bioruptor until reaching a fragment size of 200-500bp. 10-15μg of chromatin was then used for each replicate chromatin modification ChIP and 20μg for CTCF and RAD21 ChIP. ChIP for H3K27ac (Diagenode: C15410174), H3K36me3 K3K36me3 (Abcam:ab9050), CTCF (Diagenode:C15410210) and RAD21 (Abcam: ab992) was then performed as in Lee et al., 2006. Libraries were prepared using the Nextera adaptors and sequenced 50 or 75bp reads.