CD9 and melanoma: Anti‐CD9 monoclonal antibodies (Ab) were found to specifically inhibit the trans‐endothelial migration of melanoma cells.37 We have shown that anti‐CD9, but not anti‐CD133, Ab enhances the nuclear uptake of EVs in recipient cells (Figure 1C).23 This effect is greater in melanoma cells than in mesenchymal stromal cells (MSCs), presumably because of the higher expression level of CD9 in cancer cells in comparison to stromal cells.