In a cohort of 2650 Crohn’s disease cases, HLA-B*08:01 and HLA-C*07:01 (which are in tight linkage disequilibrium with each other and with the class II genes of the haplotype) but not HLA-A*01:01 were significantly associated with good prognosis (Appendix 3—table 7). This evidence concerns the gene HLA-B and Crohn disease.