Different expression levels of SEC62 in benign and borderline melanocytic tumors showed a clear correlation with biological behavior in our study: whereas benign melanocytic lesions including CN and BN express SEC62 at comparably low levels, borderline lesions, such as SN, which have a markedly higher risk for malignant transformation into MM, harbor significantly higher levels of Sec62. Here, SEC62 is linked to Miyoshi myopathy.