Total RNA was extracted from LP1 cells by lyses in TriFAST (Euroclone, EMR507100). DNA was removed with RNase-free DNase set (Qiagen, 79254) using RNeasy Mini Kit (Qiagen, 74104). TAIL Iso-seq libraries were constructed using the PCR-cDNA Barcoding Kit (Oxford Nanopore Technologies, SQK-PCB114.24) according to the manufacturer's protocol.