In a study of 102 primary melanomas by Curtin et al., mutations and/or copy number increases of KIT were present in 39% of mucosal and 36% of acral melanomas, in 28% of melanomas occurring in chronically sun-damaged skin as evidenced by dermal elastosis, but not in any (0%) melanomas on skin without chronic sun damage [8]. This evidence concerns the gene KIT and acral lentiginous melanoma.