ChiP were performed following manufacturer instructions using iDeal ChIP-seq kit for transcription factors and for histones (Diagenode). For this, Ewing cell lines were fixed for 10 minutes with 1% of methanol-free formaldehyde (28908, Thermo-Scientific). Chromatin was sonicated (Bioruptor, Diagenode) for 20 cycles (30-sec on, 30-sec off) set at position “high” to generate DNA fragments with an average size around 150-300pb. The library were constructed using TruSeq ChIP library preparation kit (Illumina) according to manufacturer recommendations