Thanks, Marilyn, for this informative article. Skin cancer is something we roommates have in common. I see the dermatolgist every six months. She often found actinic keratoses on my face. The big excitement came when an apparently unexciting bump with no pigment to the side of my left knee cap turned out to be melanoma. It had not spread, thank goodness. Beware, readers. Lather on that sunscreen and wear a big brimmed hat.