RNA was extracted using Qiagen RNeasy mini kit (Qiagen, Hilden, GER). RNA quality was checked using Agilent RNA 6000 Nano Kit (Agilent Technologies, Santa Clara, US), RNA concentration was measured with Nanodrop (Thermo Fisher Scientific, Waltham, US). 500 ng of RNA was used as input for library preparation using the Illumina TruSeq Stranded mRNA library prep kit (Illumina, San Diego, US) according to the manufacturer's instructions. Libraries were quality checked on a Fragment Analyzer (Agilent Technologies) and concentration was measured with Qubit dsDNA HS Assay kit (Thermo Fisher Scientific). Libraries were pooled and sequenced on a HiSeq4000 (Illumina).