As concerns CD, data are conflicting: in a recent paper, our group reported decreased serum BDNF concentration in adult patients, both at the diagnosis and after a one-year gluten-free diet (GFD) [21], whereas Margoni et al. showed higher serum values of BDNF in pediatric CD patients than in healthy controls, which further increased after more than one year of GFD [22]. The gene discussed is BDNF; the disease is Cowden disease.