Eustachian tube is much more than a tube: it is a fundamental organ for the fuctioning of the middle ear, especially in children up to 6 years of age, where the morphology of the tube is shorter and less angled than thos of older children. Moreover, It has an innate and an adapted immunity, and is reponsible for the regulation of the ear's temperature and humidity. Professor Paola Marchisio (University of Milan, Italy) underlines how these characteristic are fundamental in order to prevent any possible damage of the Eustachian tube mucosa.