Surprisingly, quantitative analysis of the MICA-containing exosomes from the melanomas yielded some interesting results: the signal from Ma-Mel-55 exosomes was higher than that of Ma-Mel-86c exosomes and reached a plateau at lower exosome concentration (Fig. 3b), even though the amounts of MICA and CD9 protein in the exosome preparation from Ma-Mel-55 were lower than in Ma-Mel-86c, when compared by Western blot (Fig. 3c). Here, CD9 is linked to melanoma.