Alegre and collaborators underlined the possible prognostic role of exosomes with a study that examined the presence of biomarkers such as melanoma inhibitory activity (MIA), S100B, and tyrosinase-related protein 2 (TYRP2) in exosomes obtained from the serum of healthy donors, metastatic melanoma, and melanoma disease-free patients. The gene discussed is S100B; the disease is melanoma.