CCND1 and acral lentiginous melanoma: Genetic alterations in different members of these pathways have been associated with the pathogenesis of distinct types of primary melanomas: high frequency of BRAF or NRAS mutations (which are mutually exclusive) is mostly frequent in melanoma on skin without chronic sun-damage, whereas CyclinD1 or cKIT amplifications are prevalent in CSD or acral melanoma, respectively.