In an attempt to elucidate the potential mechanism by which MYO1B regulates nuclear AKT activation, we investigated the role of PTEN, a well-known negative regulator of PI3K-AKT signal pathway, because nuclear PTEN has also been demonstrated for many years in melanoma cells and epithelial thyroid tumors (Gimm et al., 2000, Whiteman et al., 2002). This evidence concerns the gene MYO1B and melanoma.