Researchers focused on developing an innovative sweat test (bubble test) suitable to distinguish CFTR-dependent from CFTR-indipendent sweat gland secretion. Bubble test results will be compared to those obtained by another new sweat test (evaporimetry test). Both the tests aim to increase the discriminating power in nonclassical forms of CF disease and to detect significant differences among CF, non CF and carriers. They could be useful for managing efficacy of new CF therapies. Preliminary assays were performed in Verona, then the project will be carried out in Brussels and Paris labs.