Funding for this research was provided by:
EPISTOP Project (602391-2)
EPIMARKER Project (STRATEGMED3/306306/4/2016)
Received: 7 November 2017
Accepted: 10 January 2018
First Online: 29 January 2018
Ethics approval and consent to participate
: The study was assessed by the Bioethical Committee in Children’s Memorial Health Institute, Warsaw, Poland and the ethics approval was obtained.
: Not applicable.
: The authors declare that they have no competing interests.
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