Cells were crosslinked for 10 minutes with 1% formaldehyde, which was quenched with 125mM glycine. The cells were washed 3X with ice cold PBS+protease inhibitors+PMSF, and scraped into tubes. Chromatin was sheared in a Diagenode Bioruptor Pico to 150-600bp fragments. Input chromatin was saved for "input sample" and the remainder of the chromatin was pulled down using streptavidin beads. Bound chromatin and input DNA samples had the crosslinks reversed, the DNA was purified by phenol/chloroform extraction and ethanol precipitation, and the purified DNA samples were submitted to Beijing Genomics Institute for Library Generating and Sequencing. Library generated by Beijing Genomics Institute