library_construction_protocol: Cells were then lysed with 1% SDS lysis buffer (1% SDS, 10mM EDTA (pH=8), 50mM Tris-HCl (pH=8)) containing protease and deacetylase inhibitors, and sonicated for 5 min with settings of PIP 140, DF 5%, cpb 200 on a Covaris E220 (Covaris Inc., Woburn, MA) to obtain 200-600bp chromatin fragments. libraries were constructed from 2 ng of DNA, using the ThruPLEX DNA-seq kit (#R400427, Rubicon Genomics), according to the manufacturer's protocol; finished libraries were quantified by the Qubit dsDNA High-Sensitivity Assay Kit (#32854, Thermo Fisher Scientific), by an Agilent TapeStation 2200 system using D1000 ScreenTape (# 5067-5582, Agilent), and by RT-qPCR using the KAPA library quantification kit (# KK4835, Kapa Biosystems), according to the manufacturers' protocols; ChIP-seq libraries were uniquely indexed in equimolar ratios, and sequenced to a target depth of 40M reads on an Illumina NextSeq500 run, with single-end 75bp reads.