library_construction_protocol: 10 000–50 000 cells were treated with cell lysis buffer, and nuclei were collected by centrifugation for 5 min at 500 g. Transposition was performed and high-throughput DNA sequencing library was obtained using TruePrep DNA Library Prep Kit V2 for Illumina kit (TD501; Vazyme Biotech). The library products were then enriched, quantified, and sequenced on a Novaseq 6000 sequencer (Illumina) by using the PE150 model.