Tumor samples were harvested and dissociated into single-cell suspensions 9 days after the final dosage. Dead cells were excluded using a dead cell removal kit (Miltenyi Biotec). The single-cell suspensions were then stained with TotalSeq™-C Mouse antibody. These suspensions were subjected to final cell counting on a Countess II Automated Cell Counter (Thermo Fisher) and diluted to a concentration of 700-1000 nuclei/µL. We constructed 3′ single-nucleus libraries using the 10x Genomics Chromium Controller and followed the manufacturer's protocol for 3′ V3.1 chemistry with NextGEM Chip G reagents (10x Genomics). The final library quality was assessed using a TapeStation 4200 (Agilent), and the libraries were quantified by Kapa qPCR (Roche)