Moles are non harmful growths of the skin that are caused by an increased production of skin cells in one particular area of the skin. If a mole begins to change then it means that the cells have mutated into potentially harmful cancer cells. This happens because of skin damage from the sun (sun burn). The more your body has to reproduce skin cells the more likely it becomes that it will make a mistake in the genetic makeup of the cells and makes a non harmful cell into a cancerous one. This is why skin cancer is the most common cancer the skin being the largest and most exposed organ in the body must regenerate rapidly to meet the demands we put on it. It’s our first line of defense against everything that can harm us. That means when our bodies are under attack it is always harmed.