In a recent, multicentre Italian study, the diagnostic accuracy of serum zonulin determination was evaluated in 86 patients with either self-reported or double-blind confirmed NCGS, 59 patients with diarrhoea-predominant IBS (IBS-D), 15 patients with CeD and 25 asymptomatic controls. The gene discussed is HP; the disease is cranioectodermal dysplasia.