Fresh cells were subject to CUT&RUN for H3K27me3. DNA was extracted with phenol/chloroform/isoamyl alcohol NEBNext Ultra II DNA Library Prep Kit for Illumina CUT&RUN was performed as described in Skene and Henikoff eLife 2017;6:e21856 DOI: 10.7554/eLife.21856 DNA was purified by phenol/chloroform/isoamylalcohol extraction followed by glycogen/ethanol precipitation NEBNext Ultra II DNA Library Prep Kit for Illumina