MAPK1 and melanoma: Recently, exosomal miR-106b-5p derived from melanoma cells was shown to activate ERK pathway in melanocytes by targeting Eph receptor A4 (EphA4), which resulted in the downregulation of E-cadherin level and upregulation of mesenchymal proteins (N-cadherin and fibronectin), thus promoting an invasive capacity of melanocytes [45].