Received: 6 August 2019
Accepted: 28 February 2020
First Online: 3 April 2020
Ethics approval and consent to participate
: This study was approved by the Ethical committee of the Hospital Universitario Virgen del Rocío with reference 33160034. All patients older than 18 consent to have residual material tested for scientific purposes according to the Spanish legislation of 3 July 2007, unless they stated differently by written agreement.
: Not applicable.
: All the authors declare that no competing interests exist.