Funding for this research was provided by:
Guangdong science and technology project (2012B031800077)
Text and Data Mining valid from 2020-01-14
Received: 10 October 2019
Accepted: 22 December 2019
First Online: 14 January 2020
Compliance with ethical standards
: The Research Ethics Committee of the Third Affiliated Hospital of Sun Yat-sen University approved the collection of tissue samples for research.
: The authors declare that they have no conflict of interest.