library_construction_protocol: Cells were washed, trypsinized, centrifuged, and resuspended in serum-free growth medium before fixing them in 0.1% formaldehyde for 2 minutes and subsequent quenching with glycine at twice the molar concentration of formaldehyde for 5 minutes. The cells were centrifuged at 4 °C for 4 minutes at 1,300 x g and the pellet was resuspended in CUT&Tag wash buffer (20 mM HEPES-NaOH pH 7.5, 150 mM NaCl (Sigma-Aldrich, 71386), 500 µM Spermidine (Sigma-Aldrich, S0266), 1x Complete protease inhibitor EDTA-free (Roche, 5056489001)) prior to slowly freezing the cells with 10% DMSO. CUT&Tag was performed on 100,000 fixed frozen cells per condition as described by Kaya-Okur et al. 2019 and 2020. Briefly, cells were bound to concanavalin A-coated magnetic beads (Bangs Laboratories, 86057) and incubated with primary antibody overnight, followed by incubation with secondary antibody and later the CUTANA pAG-Tn5 enzyme (EpiCypher, 15-1017). Subsequently, the cleavage was induced and then the DNA was released, purified, and barcoded by amplification with barcoded primers for 13 cycles. Lastly, the libraries were purified and pooled.