For BRD2, BRD4 and MED1, 72x10^6 cells, were crosslinked with 1% PFA for 10 min at RT. ChIP was performed essentially as previously described (Roe, J.S., et al., BET Bromodomain Inhibition Suppresses the Function of Hematopoietic Transcription Factors in Acute Myeloid Leukemia. Mol Cell, 2015. 58(6): p. 1028-39). Libraries for ChIP-seq were done as previously described (Hasson D., et al., The octamer is the major form of CENP-A nucleosomes at human centromeres. Nat Struct Mol Biol. 2013 Jun;20(6):687-95).