RNA was extracted from cultured cells using AllPrep DNA/RNA/Protein Mini (Qiagen, Hilden, Germany). Indexed cDNA libraries were prepared using the TrueSeq Stranded mRNA Sample Preparation Kit (Illumina, San Diego, CA, USA). Multiplexed libraries were loaded onto a NovaSeq 6000 system (Illumina, San Diego, CA, USA), and sequences were generated using a 200-cycle kit.