IL17A and inflammatory bowel disease: Experimental colitis mice models revealed IL-23 as a key cytokine that drives the intestinal inflammation23, whereas human studies carried out in Inflammatory Bowel Disease (IBD) patients have identified single nucleotide polymorphisms in many genes encoding for proteins involved in the IL-23/IL-17 pathway24 as well as increased levels of IL-23 and IL-17 cytokines23.