Cells were isolated from tumor tissues using GEXSCOPE Nuclear Extraction Buffer (adding RNase inhibitor and DTT before use, the final concentrations of the two are 0.2 U/µL, 1 mM, respectively). Single-cell suspensions at a concentration of 1 × 105 cells/mL in PBS were prepared. Single-cell suspensions were loaded onto microfluidic devices and scRNA-seq libraries were constructed according to Singleron GEXSCOPE protocol using GEXSCOPE Single-Cell RNA Library Kit (Singleron Biotechnologies), which included cell lysis, mRNA trapping, labeling cells (barcode) and mRNA (UMI), mRNA reverse transcription, cDNA amplification, and finally cDNA fragmentation.