This is supported by the association of PTPN22 and the OLIG3/TNFAIP3 locus with other autoantibody-associated autoimmune diseases, such as systemic lupus erythematosus, Graves disease and type 1 diabetes [5,7,8,15-17], but not with those autoimmune/inflammatory disorders not associated with autoantibody production, such as ulcerative colitis, Crohn's disease and ankylosing spondylitis [5,18,19]. Here, PTPN22 is linked to Crohn disease.