library_construction_protocol: Cells were crosslinked with 1% PFA at room temperature for 10 minutes, quenched with 125 mM Glycine, and rinsed twice with 1X PBS. Cells were lysed and sonicated at 4 °C using a Bioruptor Sonicator into 100-600 bp fragments. The samples were incubated overnight at 4 °C with Dynabeads Protein A, which had been pre-coated with 5 µg anti-SOX9 (Millipore, AB5535). The ChIP samples were then washed, eluted, and reverse cross-linked by overnight incubation at 65 °C. Afterward, ChIP-DNA was purified by Phenol:Chloroform:Isoamyl Alcohol and mixed with 5% spike-in mouse gDNA for ChIP-seq. ChIP-Seq library preparation and sequencing reactions were conducted at GENEWIZ, Inc/Azenta US, Inc. (South Plainfield, NJ, USA). NEB NextUltra DNA Library Preparation kit was used following the manufacturer's recommendations. Sequencing was performed using a 2x150 Paired End (PE) configuration on Illumina HiSeq 4000.