The upregulation of the IL23R in CRC is of interest in view of previous reports on significantly elevated mucosal levels of IL23R mRNA in Crohn's disease (Kugathasan et al, 2007; Holtta et al, 2008) and more recent reports linking an IL23R polymorphism to the development of inflammatory bowel diseases, typically with an increased risk of CRC (Lakatos et al, 2008; Einarsdottir et al, 2009; Silverberg et al, 2009; Yang et al, 2009). This evidence concerns the gene IL23R and Crohn disease.