Conflict of interest: K. Zeder has nothing to disclose. Conflict of interest: A. Avian has nothing to disclose. Conflict of interest: G. Bachmaier has nothing to disclose. Conflict of interest: P. Douschan reports personal fees and non-financial support from Actelion and GSK, non-financial support from AstraZeneca, Bayer, MSD, Novartis, Teva and Boehringer Ingelheim, outside the submitted work. Conflict of interest: V. Foris reports personal fees and non-financial support from Boehringer Ingelheim, GSK and MSD, non-financial support from Actelion, Chiesi, BMS and Menarini, outside the submitted work. Conflict of interest: T. Sassmann has nothing to disclose. Conflict of interest: N. Troester has nothing to disclose. Conflict of interest: L. Brcic has nothing to disclose. Conflict of interest: M. Fuchsjäger has nothing to disclose. Conflict of interest: L.M. Marsh has nothing to disclose. Conflict of interest: B.A. Maron has nothing to disclose. Conflict of interest: H. Olschewski reports grants from Bayer, Unither Pharmaceuticals, Actelion Pharmaceuticals Ltd, Roche, Boehringer Ingelheim and Pfizer Inc., personal fees from Gilead Sciences Inc., Encysive Pharmaceuticals Ltd and Nebu-Tec, personal fees and non-financial support from Bayer, Unither Pharmaceuticals, Actelion Pharmaceuticals Ltd, Pfizer Inc., Eli Lilly, Novartis, AstraZeneca, Boehringer Ingelheim, Chiesi, Menarini, MSD and GSK, outside the submitted work. Conflict of interest: G. Kovacs reports personal fees and non-financial support from Actelion, Janssen, Bayer, GSK, MSD, Boehringer Ingelheim, Novartis, Chiesi, Vitalaire, Ferrer and AOP, outside the submitted work.