Moles on the skin are not usually hereditary because skin moles are not genetic diseases. Skin moles are also not contagious because they are not infectious diseases. Skin moles are a common type of benign skin tumors. If skin moles are frequently rubbed and irritated, they are prone to malignant transformation, and will turn into melanoma and basal cell carcinoma after malignant transformation. For skin moles on the body, if they are large in size, unclear in boundary, uneven in color, growing fast, rough in surface, or even ulcerated, it is necessary to undergo surgical excision as early as possible and do pathological diagnosis to prevent malignant transformation. Early detection, early diagnosis and early treatment are the keys to prevent malignant transformation of skin moles.