ChIP was performed as previously described [32] with some modifications. Briefly, ChIP assays were carried out on 5610 5 NTera-2 and RNAi-treated cells. Cells were harvested by trypsinization, washed, and resuspended to 2610 6 cells/ml in PBS with 20 mM sodium butyrate. The protein-DNA complexes were fixed using 1% formaldehyde for 8 min, and crosslinking fixation was stopped by adding glycine to a final concentration of 125 mM for 5 min. Crosslinked cells were washed twice with cold PBS/20 mM butyrate, resuspended in 100 ml of lysis buffer (50 mM Tris-HCl at pH 8, 10 mM EDTA, 1% SDS, 1 mM PMSF, and 20 mM sodium butyrate supplemented with a fresh protease inhibitor cocktail (Sigma) and then sonicated to an average size of 250 bp by a MISONIX Sonicator 3000 for 30 min (with pulses of 30 s on and 30 s off). We used 5 mg of anti-Sin3A, 20 mg of anti-MeCP2 (sc-994X and sc-20700X; Santa Cruz Biotechnology), 5 mg of anti-STAT3 (05-485; Upstate-Millipore, New York, NY, USA), 5 mg of anti-CBP, 5 mg of anti-p300, 20 mg of anti-polII (sc-369X, sc-585X and sc-899X; Santa Cruz Biotechnology), 5 mg of anti-H3K9Ac, 5 mg of anti-H3K14Ac (06-942 and 06-911; Upstate-Millipore), and 2.5 mg of anti-H3K4me3 (ab8580; Abcam, Cambridge, MA, USA) for immunoprecipitation, which was performed at 4uC with the indicated antibodies by incubation with Protein A Dynabeads (Invitrogen) equilibrated with 1 ml RIPA buffer (10 mM Tris-HCl at pH 7.5, 1 mM EDTA, 0.5 mM EGTA 1% Triton X-100, 0.1% SDS, 0.1% Na-deoxycholate, and 140 mM NaCl) and protease inhibitors for 2 h. The immunocomplexes were further incubated with chromatin at 4uC overnight. The bound fraction was isolated by Protein A Dynabeads according to the manufacturer's instructions, and the immunoprecipitated complexes were eluted by using 300 ml of elution buffer (20 mM Tris-HCl at pH 7.5, 5 mM EDTA, 50 mM NaCl and 20 mM sodium butyrate) for 30 min at 65uC then for 10 min at room temperature on a rotator. Chromatin was eluted from the antibody and de-cross-linked by added of 30 ml pronase (20 mg/ml) and 1 ml CaCl 2 (1 M) then incubating it at 42uC for 2 h and 65uC for 6 h. The immunoprecipitated DNA was recovered by a PCR purification kit (Qiagen) according to the manufacturer's instructions, and the purified samples were analyzed by real-time quantitative PCR using an SYBR Green master mix and a LightCycler 480 sequence detection system (Roche Applied Science, Mannheim, Germany). PCR primers were designed using the software program Primer Express (Roche Applied Science), and the amplification primers are listed in Table S2 . For each sample, the PCR analysis was performed in triplicate, and the bound fraction was compared with 1:40 diluted input DNA of 1610 5 cells. The results are reported as the ratio of immunoprecipitated (IP) DNA to input DNA (IP/input). To obtain relative occupancy values, the IP/input ratio was further normalized to the level observed at a control region, h, which was defined as 1.0. Values of NTera-2 cells were compared to those of RNAi-treated samples.