As representative of the characterization approach applied, the NTA histogram of circulating EVs isolated from the plasma of a MM patient, enrolled in the study, with confidence interval in red reporting the concentration and specific particle size of EVs, is shown in Fig. S2A together with the FCM analysis of the double positivity for CD9/CD63, CD9/CD81 and CD63/CD81, that we utilised to perform the identification of circulating EVs [8] (Fig. S2B). The gene discussed is CD81; the disease is Miyoshi myopathy.