If your skin has been kissed by the sun one too many times, chances are your arms are speckled with moles. Though pre-existing moles only account for 20-40 percent of melanoma cases, the number of moles on your right arm could help assess how high your chances are for developing melanoma. According to a recent study, researchers took data from nearly 3600 caucasian female twins from 1995 to 2003 and discovered that the moles found on the right arm, above the elbow, predicted more precisely the total amount of moles covering the rest of the body. In fact, if a woman has over seven moles on her arm, she has nine times the risk of having over 50 moles on her body. And if she has more than 11, she most likely has over 100 moles total, putting her at a much higher risk for developing melanoma. Yikes! Another great reason to visit your derm annually!