Circulating Melanoma Cells in Metastatic Patients Treated With Selective BRAF Inhibitors

Inclusion Criteria: * Fourth stage Melanoma patients with both measurable and not measurable lesions undergoing treatment with selective B-RAF inhibitors will be included. To determine the prevalence of CMC-positive patients in IV stage Melanoma, patients without mutated B-RAF undergoing chemotherapy and/or vaccines will be also enrolled at baseline, as part of study protocols approved and activated in the participating centers. * Informed written consent. Exclusion Criteria: * Inadequate compliance to multiple blood draws (baseline, 15 days, 1th month, 4th month, and/or at progression) as scheduled in this adjunctive biologic study for patients carrying B-FAF mutation; inadequate compliance to adjunctive blood draws, as scheduled at baseline for BRAF wild-type * Previously exposure to immunological treatment.