HNF4A and inflammatory bowel disease: To date, GWAS successfully identified genetic loci that contribute to IBD pathogenesis, including genes encoding barrier function proteins (GNA12 and HNF4A), innate and adaptive immune regulatory proteins (NOD2, CARD9, IL23R, and TNFSF15), autophagy proteins (ATG16L1, IRGM, and LRRK2), and ER stress proteins (XBP1)10,11,21.