Received: 13 June 2018
Accepted: 6 March 2019
First Online: 18 March 2019
: All cell lines and parent cell lines of respective subclones were obtained by ATCC and DSMZ, which apply highest ethical standards for obtaining cell lines from biomedical research partners. Therefore, further ethical approval was not required to use these cell lines. The animal experiments were approved by the North Rhine-Westphalia State Agency for Nature, Environment and Consumer Protection 84–02.04.13.A230.
: Not applicable
: The authors declare that they have no competing interests.
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