Article History
Received: 17 July 2018
Accepted: 27 July 2018
First Online: 7 August 2018
Compliance with ethical standards
:
: Luca Filippi, Orazio Schillaci, and Oreste Bagni declare that they have no conflicts of interest.
: This article does not contain any studies with human participants or animals performed by any of the authors.
: Not applicable, this is a Letter to the Editor.