Advanced malignant melanoma lesions in PTEN-deficient UV-irradiated HGFtg/+ mice were often associated with metastasis as well (compared with PTEN-WT UV-irradiated HGFtg/+ mice, Fisher exact test p = 0.0248; Figures 1B and 1C), implying that PTEN deficiency may play an important role in melanoma progression. Here, PTEN is linked to melanoma.