Constitutive activation of the Ras-Raf signaling pathway in metastatic melanoma is associated with poor prognosis.

Genes of the Raf family encode kinases that are regulated by Ras and mediate cellular responses to growth signals. Recently, it was shown that activating mutations of BRaf are found with high frequency in human melanomas. The Ras family member most often mutated in melanoma is NRas.