In an healthy person, gene expression in blood can reflect individual-specific genetic variation, responses to environmental exposures, to food intake and to exercise. It has been found to vary significantly by age, gender and time of day. In disease, blood transcriptomics may provide a ‘‘molecular signature’’ that specifically correlate to a disease leading to a diagnosis, an evaluation of patients’ response to pharmacologial treatments as well as to a more objective stratification of patients.  Furthermore, altered genes and pathways may provide a better understanding of the pathological process in a living individual. Peripheral blood gene expression signatures have recently been reported in a variety of conditions. In particular, pilot studies have identified alterations of the blood gene expression pattern potentially correlated to neurodegeneration in diseases such as Alzheimer's, Multiple Sclerosis, Huntington's and Parkinson's. As a result several gene signatures, specific pathways and candidate genes have been proposed as biomarkers. Aim of this project is to identify gene signatures in peripheral blood associated to early Parkinson’s disease to set up a new diagnostic kit as well as to provide insights into the molecular mechanisms of the disease.