Received: 28 September 2018
Accepted: 17 February 2019
First Online: 28 February 2019
: SDL and JN share first author status. AK and TZP share last author status.
: The study was ethically approved by the Sahlgrenska Academy Medical Faculty Research Committee, Gothenburg, Sweden (768–14). The requirement for informed consent was waived by the ethical committee since the patient material was stripped from direct subject identifiers. Prior to surgery, all patients have approved storage of material in the local medical biobank for clinical and research purposes.
: Not applicable.
: The authors declare that they have no competing interests.
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