The expression levels of tight junction genes (duodenum: Occludin, ZO-1, and E-Cadherin; ileum: Occludin, ZO-1, Claudin, and E-Cadherin; cecum: Occludin and Claudin; colon: Claudin; rectum: Occludin and ZO-1) were significantly lower (P < 0.05) in the HED group than those in the ND group (Supplementary Figure 1C). The gene discussed is CDH1; the disease is hypohidrotic ectodermal dysplasia.