These observations are consistent with the view that these mutations are an early event in melanoma, required for initiation but not involved in progression (Platz et al.,2008), although there is one study which suggested that BRAF and NRAS mutations are more frequent in cells of the vertical growth phase of a melanoma than in the radial growth phase suggesting a selection for cells containing the mutations (Greene et al.,2009). Here, BRAF is linked to melanoma.