library_construction_protocol: OSM, SD36-treated HeLaS3 (5 × 10^4 cells) was pretreated with 200 U/mL DNase (Worthington) for 30 min at 37 °C to remove free-floating DNA and digest DNA from dead cells. Then this medium was washed with DPBS. After cell harvesting through TrypLE Express, cell lysis was performed by adding a cold lysis buffer (48.5 μL RSB (resuspension buffer; 10 mM Tris-HCl pH 7.4, 10 mM NaCl, and 3 mM MgCl2 in water), 0.5 μL 10% NP-40, 0.5 μL 10% Tween-20, 0.5 μL 1% Digitonin). This cell lysis reaction was incubated on ice for 3 min. After lysis, 1 mL of RSB containing 0.1% Tween-20 (without NP-40 or digitonin) was added, and the tubes were inverted to mix. Nuclei were then centrifuged for 10 min at 600 r.c.f. in a pre-chilled (4 °C) fixed-angle centrifuge. The supernatant was removed with two pipetting steps, as described before, and nuclei were resuspended in 50 μL of transposition mix (25 μL 2 × TD buffer, 2.5 μL Tn5 transposase, 16.5 μL PBS, 0.5 μL 1% digitonin, 0.5 μL 10% Tween-20, and 5 μL water) by pipetting up and down six times. Transposition reactions were incubated at 37 °C for 30 min in a thermomixer with shaking at 1000 r.p.m. Reactions were cleaned up with MinElute Reaction Cleanup Kit. Reactions were pre-amplified for 5 cycles using NEBNext High-Fidelity 2x PCR MasterMix (M0541L; NEB) with adapter primers. The amplification profiles were manually assessed to determine the number of additional cycles to amplify as previously described. The final amplified library samples were stored at -80 °C for ATAC-seq after library purification with AMPure XP (A63880; Beckman). Libraries were validated using the Agilent High Sensitivity D1000 kit (5067-5584, 5067-5585; Agilent) and were subjected to high-throughput sequencing using the Illumina HiSeq 2500 Sequencer.