The effect of IL-23 depends on its binding to IL-23R, a heterodimer of the IL-12RB1 subunit22, which was identified as an additional candidate gene in some autoimmune and inflammatory diseases such as inflammatory bowel disease, psoriasis, Graves’ ophthalmopathy, ankylosing spondylitis, and multiple sclerosis23, 24. Here, IL12RB1 is linked to inflammatory bowel disease.