library_construction_protocol: 2 weeks after gRNA virus transduction, cells were harvested with Accutase, and cell concentration and cell number were assessed with a Countess II cell counter (Invitrogen) and Trypan Blue (Invitrogen). Library preparation was completed using the CUT&RUN Library Prep Kit with primer set 1 (Epicypher 14-1001). Libraries were sequenced on an Illumina Nextseq 2000 with a coverage of at least 5 million reads per sample.