HNF4A and ulcerative colitis: Dysregulation of the HNF4A gene is linked to several gastrointestinal disorders including colitis and colon cancer and a single nucleotide polymorphism in the HNF4A gene region is associated with ulcerative colitis (Ahn et al., 2008; Chellappa et al., 2012; Tanaka et al., 2006; Oshima et al., 2007; Barrett et al., 2009).