On the other hand, M Kathryn Leonard et al. described in great detail how much the melanomas arising in animal species, such as mouse models, could be very aggressive and how the creation of genetically modified mouse models (GEMMs) can be of help to better understand the pathogenesis of primary melanoma and its potential therapy (CDK4 R24C, surviving, and NME1/NME2) [22]. This evidence concerns the gene CDK4 and melanoma.