library_construction_protocol: Samples tissues were immediately frozen in liquid nitrogen or stored at − 80 ° C after the surgery.Total RNA of tissue was extracted using the RNeasy Mini Kit (Qiagen, USA) according to the manufacturer's protocol. Then the extracted RNA was qualitatively controlled and quantified by Nanodrop. The RNA library was constructed using TruSeq RNA sample preparation kit and TruSeq Small RNA (Illumina, USA). After purification, the library was quantified with Qubit 8000 (Life Technologies, USA) and verified with Agilent 2100 (Agilent Technologies, USA) to confirm the fragment size