Received: 20 June 2019
Accepted: 12 August 2019
First Online: 16 August 2019
Ethics approval and consent to participate
: The study was approved by the Ethics Committee of Shengjing Hospital of China Medical University and conformed to the provisions of the Declaration of Helsinki. Data of our present study was downloaded from an open database TCGA, so there was no informed consent from participants.
: Not applicable.
: The authors declare that they have no competing interests.