TNF and inflammatory bowel disease: To date there is still not a demonstration of the involvement of these genes in IBD, except for three SNPs: rs9268877, rs9268858, and rs9268480; the association with this locus appears to be mainly linked to polymorphisms in the TNFα gene promoter (308G → A polymorphism increases the risk for CD, 238G → A polymorphism reduces the levels of TNFα in patients with UC; −857C polymorphism increases the risk of IBD only in patients with the common mutations of NOD2/CARD15).