In the melanoma, both the wild-type and the variant PTEN alleles were detected by Sanger sequencing, the PTEN protein was shown to be expressed by immunohistochemistry, and staining for phospho-AKT was weak; conversely, in the thyroid carcinoma only the variant allele was detected, supporting LOH; consistently, IHC analysis of PTEN was negative, whereas there was an intense staining for phospho-AKT (Figure 3). This evidence concerns the gene PTEN and melanoma.