Competing interests: MK: Outside the submitted work. Consultancy fees from Abbvie, Pfizer, Kiniksa, Flexion, Galapagos, Jansen, CHDR, Novartis, UCB; all paid to the institution. Royalties from Wolters Kluwer, Springer Verlag; all paid to the institution. Research grants from IMI-APPROACH. FR: Outside the submitted work. Consultancy fees from Genevrier, Pfizer, Bone Therapeutics, Grunenthal, Sanofi, Pierre Fabre, Expanscience. Grants from SFR, Arthritis Foundation. Stock options from Peptinov, Scarcell, Skindermic. FB: Outside the submitted work. Consulting fees from AstraZeneca, Boehringer Ingelheim, Bone Therapeutics, Cellprothera, Galapagos, Grunenthal, GSK, Eli Lilly, Merck-Serono, MSD, Nordic Bioscience, Novartis, Pfizer, Roche, Sandoz, Sanofi, Servier, UCB, Peptinov, 4P Pharma. Grants from TRB Chemedica, Pfizer, all paid to institution. Fee for lectures from Expanscience, Pfizer. Payment for expert testimony from Pfizer, Eli Lilly. CEO and stock options from 4Moving Biotech.