IL12B and inflammatory bowel disease: These were associated with either CD (11 variants), UC (5 variants) or IBD (12 variants), with 4 of these variants located in BTNL2. BTNL2 and IL12B map to established UC and IBD risk loci and have previously been implicated in UC and IBD respectively (6p21/HLA class II/UC and 5q31/IBD respectively), whilst ARIH2 and NICN1are within the same previously described IBD locus (3p21.3/IBD) but the genes themselves have not been implicated.