Funding for this research was provided by:
National Natural Science Foundation of China (81530060, 81874224)
Received: 5 September 2019
Accepted: 26 March 2020
First Online: 6 April 2020
Ethics approval and consent to participate
: This study protocol was approved by Shandong Cancer Hospital ethics committee. The written informed consent to participate was given.
: Not applicable.
: The authors declare that they have no competing interest.