When crossed with Tyr::CreER mice and tamoxifen is rubbed on their skin, these mice develop benign melanocytic hyperplasias that fail to progress to melanoma over 15–20 monthsOn a Pten null background, these mice developed melanoma with 100% penetrance, short latency, and metastases (lymph nodes and lungs)Melanoma development was prevented by inhibitors of mTorc1 (rapamycin) or MEK1/2 (PD325901) but only whilst the drug was being administered (cessation of administration led to melanoma development). Combined rapamycin and PD325901 treatment led to shrinkage of established melanomas. This evidence concerns the gene MAP2K1 and melanoma.