PTEN and melanoma: Mutation activation of BRAF is the earliest and most common genetic change in human melanoma; mice specifically expressing BRAF(V600E) showed benign melanocyte proliferation, but did not develop melanoma after 15–20 months, and BRAF(V600E) expression combined with PTEN gene silencing could induce malignant melanoma and metastasis to lymph nodes and lungs (112).