ChIP-seq experiments were carried out as previously described (29). Briefly, cells in a 15cm plate were crosslinked by 15ml 1% PFA (ThermoFisher, #28908) in PBS with shaking for 10 minutes at room temperature. 2ml of 2.5M Gylcine was added to quench the reaction and continue shaking for 5 minutes. Crosslinked cells were then scraped and collected. Covaris E200 was used for chromatin sonication with following settings: 10% duty factor, 200 cycles per burst, and 140 peak intensity power, 10 minute. For NCI-H510 cells, antibodies wer added, then incubated with the lysate over night at 4°C with rotation for immunoprecipitation. Protein G-coupled Dynabeads (Invitrogen, #10004D) were used to pull down the immune complexes. Protease K (Roche, #3115828001) was used during reverse crosslink (65°C, 1200rpm, overnight). DNA was then purified through QIAquick PCR Purification Kit (Qiagen, #28106). Libraries were prepared by using the KAPA HTP library preparation kit (Roche, #07961901001) and sequenced on the Illumina NovaSeq 6000.