IL1B and Crohn disease: Consistently, mutations in the IL-1β gene resulted in increased protein levels and therefore, in a higher risk of colon cancer development (162) and mutations in the nucleotide binding oligomerization domain containing (NOD)-2 gene have been shown to increase NF-κB activity and IL-1β processing in patients with severe forms of Crohn's disease, indicating an association between IL-1β and the development of IBD (163).