SNAI1 and melanoma: The MAPK and the PI3K signaling pathways are known to activate NF-kB, which further induces Snail to mediate a mesenchymal phenotype in epithelial cells (56), but similar evidence for the NF-kB/Snail mechanism in melanoma is lacking (57), although Snail is a demonstrated inducer of the mesenchymal-like phenotype in melanoma (58).