JM-C has received consultancy/speaker's fees from AbbVie, Lilly, Janssen, Novartis, Pfizer, UCB, MSD, and BMS; trial participation as principal investigator for Novartis. None of these fees were related to the present manuscript. PB has received speaker and add board fees from Janssen and AbbVie, speaker fees from Lilly and projects grants from Pfizer. EM speakers bureau: AbbVie, Novartis, Pfizer, MSD, BMS, UCB, Roche, Grünenthal, Janssen, and Sanofi; paid instructor for: Janssen, Novartis, and Roche; consultant of: AbbVie, Novartis, Pfizer, and Galapagos; Grant/research support from: AbbVie, Novartis, and Pfizer. WS has received speaker honoraria from AbbVie, Amgen, Bristol Myers Squibb, Chugai, GlaxoSmithKline, Johnson & Johnson, Medac, Novartis, Roche, and UCB; advisory board honoraria from AbbVie, Amgen, Boehringer Ingelheim, Fresenius Kabi, GlaxoSmithKline, Novartis, and Sanofi; trial participation as principal investigator for AbbVie, GlaxoSmithKline, Novartis, and Sanofi. CD has received consulting/speaker's fees from Abbvie, Eli Lilly, Janssen, Novartis, Pfizer, Roche, Galapagos, Sparrow, Boehringer, and Sanofi; grant support from AbbVie and Novartis, all unrelated to this manuscript. The author(s) declared that they were an editorial board member of Frontiers, at the time of submission. This had no impact on the peer review process and the final decision.