library_construction_protocol: The column-based miRNeasy RNA isolation kit (Qiagen) was used. RNA was isolated according to the manufacturer's instructions with minor modifications (extra column-washing step with 80% ethanol before extracting the RNA with RNase-free water) To determine RNA quality and integrity we used Lab-on-Chip analysis on an Agilent 2100 Bioanalyzer (Agilent Technologies). RNA samples with an RNA integrity number above 8 were used. The TruSeq Stranded mRNA Library Prep Kit from Illumina was used to construct libraries