Funding for this research was provided by:
Hebei Province Medical Science Research Key Project (20170402, 20180616)
Received: 15 February 2019
Accepted: 4 November 2019
First Online: 12 November 2019
Ethics approval and consent to participate
: The protocols used in this retrospective study was reviewed and approved by the institutional review board of Children’s Hospital of Hebei Province. Because there was no need to collect new specimens and the clinical data was de-identified, so the consent was waived by IRB of Children’s Hospital of Hebei Province. After obtaining the IRB’ permission, we can review patient records and use these data, which were all de-identified.
: Not applicable.
: All the authors declared that they have no competing interests.