Significant differences for cytoplasmic Pin1 staining were observed between normal nevi and metastatic melanoma (P = 0.011, χ2 test), between dysplastic nevi and primary melanoma (P = 0.046, χ2 test) and between dysplastic nevi and metastatic melanoma (P = 0.016, χ2 test). This evidence concerns the gene PIN1 and dysplastic nevus.