Received: 25 June 2019
Accepted: 22 May 2020
First Online: 22 June 2020
Ethics approval and consent to participate
: Procedures were followed as outlined in accordance with ethical standards formulated in the Helsinki Declaration 1975 (and revised in 1983). Patients gave their written consent to usage of their tumor specimens, an approval was obtained from the University of Cologne Ethics Committee (reference number: 13–091).
: Not applicable.
: The authors declare that they have no competing interests.