RNA was extracted using NucleoSpin® RNA extraction kit (Macharey-Nagel) according to manufacturer's protocols. Total RNA samples were first enriched for mRNA with poly-A tails using oligo dT beads. The enriched mRNA molecules were then fragmented into small pieces, which were subsequently used to synthesize first-strand cDNA with random primers. The second strand of cDNA was synthesized using dUTP in place of dTTP. The synthesized cDNA underwent end-repair and 3' adenylation, after which adaptors were ligated to the ends of the adenylated cDNA fragments. Following this, PCR amplification was performed, and the resulting library underwent quality control. The library was circularized and further amplified to produce DNA nanoballs (DNB), which were sequenced using the DNBSEQ platform.