library_construction_protocol: CUT&RUN was performed on ~1.4-2x105 sort-purified cells using the CUTANA ChIC/CUT&RUN Kit (Epicypher) according to manufacturer protocol. Briefly, cells were permeabilized with buffer containing 0.05% digitonin. After cells were bound to activated Concanavalin A (ConA)-coated beads, cells were bound with 4 μg anti-histone H3K27me3 (Millipore), which was used to guide cleavage by pAG-MNase. After cleavage, 0.5ng E. coli spike-in DNA was added to the Stop Buffer for sequencing data normalization. Libraries were prepared with NEBNext Ultra II Library Prep Kit.