Footnotes

• Contributors SD, CF and JP participated in the conception, literature review and writing of the manuscript.

• Funding This work has been in part supported by grants from Fondazione Humanitas per la Ricerca and FIRMAD to SD, and grant SAF 2012-33560, from Ministerio de Economía y Competitividad, Spain, to JP.

• Competing interests SD has received consulting fees from and has served as a speaker, a consultant and an advisory board member for Schering-Plough, Abbott Laboratories, Merck & Co, UCB Pharma, Ferring, Cellerix, Millenium Takeda, Nycomed, Pharmacosmos, Actelion, Alphawasserman, Genentech, Grunenthal, Pfizer, Astra Zeneca, Novo Nordisk, Salix, Cosmo Pharmaceuticals, Vifor and Johnson and Johnson. JP has received consulting fees from Abbvie, Boehringer Ingelheim, Galapagos, Genentech-Roche, Ferring, Janssen, MSD, Novo-Nordisk, Pfizer, Takeda and Tigenix.

• Provenance and peer review Not commissioned; externally peer reviewed.