Two years ago, 43-year-old Maine firefighter Mike Nixon was diagnosed with malignant melanoma — the most dangerous form of skin cancer. "I had a spot develop in a weird place on my ear," he says. "It wasn't on top where you'd think people would get skin cancer, where there is sun exposure. It was up near the top part of my left ear, but underneath the fold in the shaded part — the one and only part that is shaded except the ear canal. My wife spotted it.