library_construction_protocol: TotalRNA was isolated using the ReliaPrep RNA Cell Miniprep System (Promega). Quality and quantity of isolated RNA was analyzed with the Bioanalyzer RNA Pico Chip (Agilent). cDNA synthesis and library preparation was performed with the SMART-Seq v4 PLUS Ultra Low Input RNA kit (Takara) following the manufacturer's protocol. Libraries were sequenced on a single-end run (1x100bp, dual-index) on a NovaSeq6000 (Illumina) using SP 100 v1.5 chemistry (Illumina).