SRX5904135 GSM3819864 SRP199580 SRS4824243 GSM3819864 ChIP-Seq GENOMIC ChIP Cells were cross linked in 1% formaldehyde for 10 min and then washed with PBS. Cell pellets were frozen at -80C. All cell pellets were thawed on ice, combined for a total of 19.5 million cross linked cells and resuspended in cold PBS. PBS was removed and replaced with hypotonic buffer (20mM Hepes pH 7.9, 10mM KCl, 1mM EDTA, pH 8, 10% glycerol) and cells incubated on ice for 6 min. Cells were dounce homogenized with 20 strokes on ice using a 7ml glass homogenizer. Nuclear lysates were sonicated using a Branson 250 Sonifier (power setting 4, constant duty for 12 rounds of 20 second pulses), resulting in chromatin fragments of 250-400 bp. Lysate was treated overnight at 4C with 5ug of anti-Tcf21 antibody (Sigma #HPA013189). Protein-DNA complexes were captured on Protein G agarose beads (Millipore Sigma #16-266) and eluted in 1% SDS TE buffer at 65C. After reverse cross linking, RNase A and proteinase K digestion, chromatin was purified using Qiagen PCR purification kit (Catalog #28106) sequencing libraries were generated according to Illumina DNA Sample Kit Instructions (Illumina Part # 0801– 0303, San Diego, CA) Illumina HiSeq X Ten gds 303819864 GSM3819864 GEO Accession GSM3819864