Funding for this research was provided by:
Natural Science Foundation of Heilongjiang Province (LH2019H119)
Text and Data Mining valid from 2020-02-11
Received: 25 September 2019
Accepted: 29 January 2020
First Online: 11 February 2020
Ethics approval and consent to participate
: All patients involved in this study had written informed consent and consent to use excess pathological specimens for research purposes. All the research in our study was approved by the Ethical Committee of Affiliated Hospital of Mudanjiang Medical University.
: Not applicable.
: The authors declare that they have no competing interests.