Diabetes mellitus is a common chronic disease with a huge socioeconomic burden worldwide. Type 1 Diabetes(T1D) accounts for nearly 95% of diabetes in pediatric age and a lifelong dependence on exogenous insulin. Its diagnosis is based on symptoms and/or autoantibodies, both identified too late to avoid the disease progress. Ideally, children should be screened whilst assymptomatic, when there is endogenous insulin production, but C-peptide and beta-cell function are starting to decline. Early diagnosis would allow interventions capable of preventing disease progress and/or to preserve beta-cell function, ultimately delaying/avoiding insulin dependence. Given their association with pathogenesis of diabetes, Extracellular Vesicles have emerged as potential biomarkers for diagnosis and progression of diabetes. This project proposes the development of a non-invasive biomarker of preclinical T1D, based on miRNA characterization in urine, allowing a timely identification of children that can benefit from preventive therapies and, in the future, to cure T1D.