Received: 26 February 2019
Accepted: 23 May 2019
First Online: 6 June 2019
Ethics approval and consent to participate
: Our work was conducted in accordance with the recommendations of the Ethics Committee of the Medical Faculty of the Leipzig University. The committee’s reference number is 234-14-14072014. Written informed consent for using the tissue samples was obtained from the patients.
: The authors declare that they have no competing interests.