Conflict of interest: A.U. Wells reports personal fees for consultancy and lecturing from Intermune/Roche, Boehringer Ingelheim and Bayer, and personal fees for consultancy from Gilead, outside the submitted work. Conflict of interest: K.K. Brown reports multiple lung fibrosis grants from NHLBI, personal fees from AstraZeneca, Biogen, Fibrogen, Galecto, Gilead, MedImmune, Novartis, Aeolus, ProMetic, Patara, Third Pole, aTyr, Galapagos and Boehringer Ingelheim, has a submitted grant with Roche/Genentech, and conversation under CDA only with Global Blood Therapeutics and Genoa, outside the submitted work. Conflict of interest: K.R. Flaherty reports grants and personal fees from Boehringer Ingelheim and Roche/Genentech, grants from Afferent, personal fees from Veracyte, Fibrogen, Immuneworks, Aeolus, Pharmakea, Sanofi-genzyme and Celgene, outside the submitted work. Conflict of interest: M. Kolb reports grants and personal fees from Roche, Boehringer Ingelheim, GSK and Prometic, personal fees from Gilead and Genoa, and grants from Actelion, Respivert, Alkermes and Pharmaxis, outside the submitted work. Conflict of interest: V.J. Thannickal has nothing to disclose.