CD81 and melanoma: EV derived from B16, B16-LU, and B16-LI melanoma cells were evaluated by TEM (Figure 1A), evidencing a mixture of exosomes and microvesicles ranging from 50 to 400 nm in diameter, characterized by the expression of CD81 (Figure 1B; whole western blot membrane in Figure S1), one of the proper surface markers of EV.