Moles -- the brown, slightly raised beauty spots found on most humans -- can sometimes turn deadly. This is because certain forms of skin cancer can resemble moles or form within them. However, when a cancerous mole is caught early enough, even the most aggressive type of skin cancer is treatable. The key to early detection is to monitor your moles and be on the lookout for suspicious changes. Do you know what a healthy mole is supposed to look like? Do you know what kinds of changes in moles might indicate cancer? Take this quiz to find out how much you know about spotting cancerous moles. It just might save your life.