library_construction_protocol: Before RNA extraction, pericardial fluid samples were double centrifugated at 3000 g at 4°C for 15 min and obtained supernatant was used for RNA extraction. Small RNAs were extracted using SPLIT RNA Extraction Kit (Lexogen) according to manufacturer's recommendations. Small RNA libraries were generated using Small RNA-Seq Kit (Lexogen) according to manufacturer's recommendations. The number of amplification cycles was 20 for all samples.