IFN-γ, a type II interferon, is thought to contribute to the pathological intestinal inflammation seen in irritable bowel disease (IBD) (83, 84) and TNF is widely recognised for its involvement across autoimmune conditions such as IBD, arthritis, psoriasis, and systemic lupus erythematosus (85). This evidence concerns the gene IFNG and systemic lupus erythematosus.