IL17A and ulcerative colitis: The IL17F 7383A/G mutation results in a Glu-to-Gly substitution at amino acid 126 and may cause carriers of the uncommon G allele to have lower levels of IL-17 production and activity.30 Rheumatoid arthritis, autoimmune thyroid disease, prosthetic joint infection, ulcerative colitis, asthma, and malignancies have all been associated with the IL17F 7488A/G (rs763780) and IL17F 7383A/G (rs2397084) polymorphisms, according to previous research.32–34