For example, let-7i transferred by melanoma cell exosomes can induce epithelial–mesenchymal transition in primary melanocytes via the activation of MAPK signaling.324 In addition, exosomal miR-106b-5p derived from melanoma cell contributes to the EMT process of melanocytes by targeting EphA4 to activate the ERK pathway.325 Apart from these, exosomes also play a role in regulating angiogenesis and immune cell function in tumor microenvironment and preparation of a hospitable metastatic niche in distant organs to facilitate metastasis. Here, EPHA4 is linked to melanoma.