We prepared the libraries using the 10x Single Cell Chromium Next GEM Single Cell 3ʹ GEM Library & Gel Bead Kit v3.1 (10x Genomics, Pleasanton, CA, USA) according to the manufacturer's protocol. Amplified cDNA was fragmented, end-repaired, PCR-amplified with sample indexing primers, and purified with SPRIselect beads (BECKMAN COULTER, Brea, CA, USA).