library_construction_protocol: Briefly, frozen tissue samples were rapidly added to the lysis buffer and homogenized into a liquid state using a tissue homogenizer.  The resulting tissue lysate was filtered through a 40 μm cell sieve to remove impurities and then transferred to a fresh 2 mL EP tube.  The sample was centrifuged at 500 g at 4°C for 5 minutes to collect the precipitate.  Subsequently, PB1, PB2, and PB3 solutions were added to the precipitate, with the nuclei positioned at the interface between PB2 and PB3 solutions.  Finally, the nuclei were resuspended by gentle pipetting into 50 μL of NB solution.  A cell counter was employed to count the nuclei (Thermo Fisher, USA) Sequencing libraries were prepared following the manufacturer's instructions (10X Genomics, USA) and then sequenced on the NovaSeq 6000 system (Illumina, USA).