Thus, identification of the role of IL-33 and IL1RL1 in IBD susceptibility is in line with the recent concept of shared genetic determinants for clinically distinct disorders [57], and notwithstanding the number of IBD susceptibility genes that has increased dramatically over the last several years, genes associated with the IL-33 signaling pathway have not been reported to date. The gene discussed is IL1RL1; the disease is inflammatory bowel disease.