library_construction_protocol: On day 36, cells were dissociated using TrypLE™ and papain mixture, pelleted, and nuclei were isolated following a 10x Genomics protocol for single nucleus RNA Sequencing (NucSeq) as previously reported​. Sequencing libraries for single-nuclei suspension samples were generated using 10X Genomics Chromium Single-Cell 3′ Reagent kits (Pleasanton, CA, USA, version 3.1) according to the manufacturer's menu. Briefly, nuclear suspensions were loaded onto the chromium chip along with gel beads, partitioning oil, and master mix to generate GEMs containing free RNA. RNA from lysed nuclei was reverse transcribed and cDNA was PCR amplified for 19 cycles. The amplified cDNA was used to generate a barcoded 3′ library according to the manufacturer's protocol, and paired-end sequencing was performed using an Illumina NovaSeq 6000 (San Diego, CA, USA, read 1: 28 bp and read 2: 91 bp). Library preparation and sequencing was performed by the Genomics Core, Cancer Research UK Cambridge Institute. 10X Single nucleus RNA-Seq