IGHA1 and inflammatory bowel disease: Weak and strong IgA1 to Dectin1 binding affinity was confirmed by biolayer interferometry and representative association‐dissociation curves are depicted in Appendix Fig S2E. Oppositely, IgA2 binding strength was not discriminative for RT levels between non‐IBD nor CD IgA2 (Appendix Table S3) as non‐IBD and CD IgA2 had high levels of RT regardless of Dectin‐1 affinity (Fig 1M and N).