Conflict of interest: D.G. Helou reports grants or contracts from Agence Nationale de la Recherche and Inserm Transfert, outside the submitted work. B. Crestani reports grants or contracts from Boehringer Ingelheim, BMS and Unimed, consulting fees from AstraZeneca, Boehringer Ingelheim, Glycocore, GSK and Roche, payment or honoraria for lectures, presentations, manuscript writing or educational events from AstraZeneca, BMS, Boehringer Ingelheim, Chiesi, GSK, Menarini, Novartis, Roche and Sanofi, support for attending meetings and/or travel from AstraZeneca, BMS, Boehringer Ingelheim, Menarini and Sanofi, participation on a data safety monitoring board or advisory board for BMS, Boehringer Ingelheim, CSL Behring, Glycocore, GSK and Sanofi, and is member of the board of trustee of the Fondation du Souffle, a French charity, outside the submitted work.