Melanoma progressses through 5 phenotypically distinct stages: benign nevus, dysplastic nevus, radial-growth phase, vertical-growth phase, culminating in metastatic melanoma. Environmental and genetic factors play a role in the disease progression. Oncogenic mutations in B-Raf and N-Ras activate the Raf-MEK-ERK pathway while mutations in N-Ras and PTEN activate the PI3K-AKT pathway leading to uncontrolled proliferation and cell survival. These mutations arise early during melanoma pathogenesis and are preserved throughout tumor progression....