HaCaT cells were crosslinked with 1% formaldehyde for 10 min at room temperature, and the reaction was quenched with 125 mM glycine. Cells were lysed and chromatin was sheared to 200-600 bp using a sonicator. Immunoprecipitation was performed using antibody against  (anti-C-FOS, CST 31254S). Antibody-chromatin complexes were captured by protein A/G magnetic beads, washed, and eluted. Crosslinking was reversed overnight at 65°C, and DNA was purified by phenol-chloroform extraction or spin columns. Purified ChIP DNA was used for library preparation. 20-100 ng of ChIP DNA or input DNA was used as starting material. The DNA was mixed with Endprep Mix (Twist) in a 60 μL reaction and incubated in a thermal cycler: 30°C for 20 min, 72°C for 20 min, then hold at 4°C. To the dA-tailed DNA (60 μL), 30 μL Ligation Enhancer, 5 μL Fast T4 DNA Ligase, and 5 μL DNA Adapter (Twist) were added. The reaction was incubated at 20°C for 15 min. 60 μL of Hieff NGS® DNA Selection Beads (0.6× bead-to-sample ratio) were added, incubated at room temperature for 5 min, and placed on a magnetic stand. Beads were washed twice with 200 μL of 80% ethanol and air-dried. DNA was eluted in 21 μL ddH2O, and 20 μL of eluate was recovered. The eluted ligated DNA (20 μL) was mixed with 25 μL of 2× Amplification Mix and 5 μL of Primer Mix (Twist). PCR was performed: 98°C for 1 min; 7 cycles of 98°C for 10 sec, 60°C for 30 sec, 72°C for 30 sec; final extension 72°C for 5 min; hold at 4°C. The amplified library was purified using 0.9× Hieff NGS® DNA Selection Beads (0.9× bead-to-sample ratio) following the same washing and elution protocol. The final library was eluted in 20 μL ddH2O. Library concentration was measured by Qubit 4.0 (Thermo Fisher) and fragment size distribution was assessed by 1% agarose gel electrophoresis or Bioanalyzer. Libraries were sequenced on an Illumina NovaSeq X Plus instrument with paired-end 150 bp reads (or as per actual run parameters).