Modulation of intestinal TJs by zonulin allows antigens and toxins to enter the bloodstream, triggering immune responses that can lead to several diseases in humans, in which autoimmunity plays the major role, such as celiac disease, type 1 diabetes mellitus (T1DM), multiple sclerosis (MS), rheumatoid arthritis, and inflammatory bowel diseases4–6. The gene discussed is HP; the disease is celiac disease.