MDM2 and melanoma: Conversely, they reinforce some recent results obtained in melanomas in which, despite the high levels of protein expressed, the frequency of mutations/polymorphisms in TP53 gene was not high [39], suggesting that other mechanisms acting on the protein and/or its signaling pathway, such as p53 cytoplasmic retention [40] and MDM2 overexpression [41, 42], might be involved in wild-type p53 inactivation [38].