Moles that appear in areas that are prone to friction may, not always, become malignant. Moles are generally referred to as nevi, which is a common benign skin tumor. It may be related to heredity, ultraviolet radiation and other factors. The color of the skin lesions may be black, brown, brown, etc., and the shape is mostly spots, patches or papules. The chance of moles becoming malignant is very low, but there is a possibility of malignant transformation if they are repeatedly stimulated and rubbed for a long period of time. In your daily life, you should closely observe the changes of moles. If a mole suddenly becomes bigger, deepens in color, breaks down or bleeds, it is recommended that you go to the dermatology department of a hospital in time for consultation and treatment.