For ChIPseq, cells were crosslinked with 1% formaldehyde. Crosslinking was quenched with 125mM glycine, and the cell pellets were sonicated for ChIP. ChIP samples were end-repaired, A-tailed, and barcoded adaptors were ligated. DNA purified using EconoSpin column on every steps. The adaptor ligated DNA was PCR amplified for 16 cycles with Phusion polymerase.