Total RNA was purified using a miRNAeasy micro kit (Qiagen, USA) and quantified as described previously (12 (link), 15 (link)). Purified total RNA (5 ng) was amplified following the Smart-seq2 protocol (16 (link)). cDNA was purified using AMPure XP beads (1:1 ratio, Beckman Coulter). From this step, 1 ng of cDNA was used to prepare a standard Nextera XT sequencing library (Nextera XT DNA sample preparation kit and index kit, Illumina). Samples were sequenced using a HiSeq2500 (Illumina) to obtain 50-bp single end reads. Both whole-transcriptome amplification and sequencing library preparations were performed in a 96-well format to reduce assay-to-assay variability. Quality control steps were included to determine total RNA quality and quantity, the optimal number of PCR pre-amplification cycles, and fragment size selection. Samples that failed quality control were eliminated from further downstream steps. Barcoded Illumina sequencing libraries (Nextera, Illumina) were generated utilizing the automated platform (Biomek FXp). Libraries were sequenced on the HiSeq2500 Illumina platform to obtain 50-bp single end reads (TruSeq® Rapid Kit, Illumina), generating a total of >700 million mapped reads (median of ~9 million mapped reads per sample).