design: About 5 million cells were cross-linked with 1% formaldehyde for 10 min, followed by quenching with 125 mM glycine for 5 min at room temperature. Fixed cells were washed once with 1X TBS, resuspended in cell lysis buffer (10 mM Tris-HCl pH7.5, 10 mM NaCl, and 0.5% IGEPAL), and incubated on ice for 10 min. The lysates were washed with micrococcal nuclease (MNase) digestion buffer (20 mM Tris-HCl, pH7.5, 15 mM NaCl, 60 mM KCl, and 1 mM CaCl2) and incubated for 20 minutes at 37°C in the presence of MNase (NEB, Cat# M0247S). After adding the same volume of sonication buffer (100 mM Tris-HCl pH8.1, 20 mM EDTA, 200 mM NaCl, 2% Triton X-100, and 0.2% Sodium deoxycholate), the lysate was sonicated for 15 min (30 sec-on / 30 sec-off) in Diagenode bioruptor and centrifuged at 15,000 rpm for 10 min. The cleared supernatant was incubated with the titrated amount of target antibody (2 ml antibody per 20 mg of chromatin) on rocker overnight, including anti-H3K4me1 (Mayo Clinic Epigenomics Development Lab, Lot1), anti-H3K4me3 (Diagenode, C15410003), or anti-H3K27ac (CST, 8173BC). For input library, no antibody was added. DNAs were purified using Min-Elute PCR purification kit (Qiagen) after treatment with RNase A and proteinase K. ChIP-seq libraries were prepared from 10 ng of ChIP and input DNAs with the ThruPLEX® DNA-seq Kit (Takara Bio, Cat# R400675).