Chromatin immuoprecipitation (ChIP) experiments with MCF7 cells were performed as previously described (Tsai et al, Nature, 2010. PMID:21164480). Briefly, the fragmented chromatin lysate was immunoprecipitated overnight using TRIM24 antibody. The protein-DNA complexes were washed several times and the phenol-chloroform-extracted DNA was used for library construction and sequencing. For ChIP-seq, sequencing libraries were prepared using the Illumina TruSeq DNA Sample Preparation Kit according to the manufacturer's protocol. After adapter ligation DNA was PCR amplified with Illumina primers for 15 cycles and library fragments of ~250-450 bp (insert plus adaptor) were band isolated from an agarose gel. DNA fragments were sequenced using single-end sequencing technology on Illumina HiSeq 3000 platform.