In the available data, we found higher fecal zonulin levels in children with the following diseases: IBD [25,49], pediatric nonalcoholic fatty liver disease fibrosis [50], celiac disease [51], rotavirus infection [52], but also with diseases not related to the gastrointestinal tract, such as glucose metabolism dysregulation, type 2 diabetes [53], and autism spectrum disorders [54]. The gene discussed is HP; the disease is inflammatory bowel disease.