NRAS and melanoma: Although there are conflicting reports of the presence of BRAF, NRAS and c-KIT mutations in canine mucosal melanomas, possibly reflecting the complexity and heterogeneity of cancer seen in humans, a strong parallel between human and canine mucosal melanoma is frequent in activation of the RAS/MAPK and/or PI3K/AKT/mTOR signalling pathways [57, 113] with synergistic targeted inhibition of MEK and dual PI3K/mTOR inhibiting tumour growth of a canine melanoma cell line in nu/nu athymic mice [114].