CAV1 and melanoma: First, we observed that Cav1 is strongly expressed on exosomes secreted by human melanoma cells in vitro while undetectable on both cellular extracts and exosomes from normal human cells such as for instance primary monocyte-derived macrophages (MDM) (Figure 3A), suggesting that Cav1 secreted in an exosome-embedded form may be a specific feature of melanoma cells, thus representing a potential marker for the ex-vivo analysis of tumor-derived exosomes.