CD9 and melanoma: To directly evaluate the effect of EVs in metastatic niche formation, we pre‐treated mice with seven injections during 3 weeks of 10 μg of SK‐MEL‐147 EVs enriched by serial ultracentrifugation from conditioned media of untreated cells or cells treated with the CD9 peptide, before intravenous injection of untreated melanoma cells.