Given that the 197A allele is significantly associated with the higher production of IL-17, G197A genotyping may be used to predict the susceptibility and severity of other IL-17-related diseases and complications including rheumatoid arthritis, periodontal disease, multiple sclerosis, allergic rhinitis, psoriasis, inflammatory bowel disease, and organ allograft rejection [11]. This evidence concerns the gene IL17A and inflammatory bowel disease.