library_construction_protocol: Cardiomyocytes were isolated from C57BL/6J adult mice by enzymatic dissociation. RNA was extracted from aCMs, using TRIzol Reagent (Ambion) and quantified. The libraries were generated using depleted RNA obtained from 1 µg total RNA by TruSeq Sample Preparation RNA Kit (Illumina, Inc., San Diego, CA, USA) according to the manufacturer's protocol without further modifications