library_construction_protocol: Spheroids were then collected in a 15mL falcon tube and reduced to single-cell suspension using 0.25% trypsin with DNase I (0.2 mg/mL, Worthington) and Collagenase I (5 mg/mL, Gibco) for 30 minutes at 37°C. Cells were washed 3 times in DMEM containing 10% FBS. Cells were collected by centrifugation at 450g for 5min and finally resuspended in PBS (Gibco) containing 0.04% BSA. Cell count was determined using a Countess machine (Thermo Fisher). After passing through a cell strainer (Corning), 25'000 cells were loaded into a 10x Chromium machine (10x genomics). Library preparation was performed using the Chromium GEM-X Single Cell 3' Kit (10x Genomics), followed by sequencing at Novogene.