Article History
Received: 1 August 2018
Accepted: 17 October 2018
First Online: 1 March 2019
Ethics approval and consent to participate
: This study was performed in accordance with national regulative law for the handling of biological specimens from tumour banks, the samples being exclusively available for the research purposes in retrospective studies as well as under the international Helsinki declaration.
: The authors declare that they have no competing interests.
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