Skin cancer is the most commonly diagnosed form of cancer. Most skin cancer is basal cell carcinoma or squamous cell carcinoma (both types known as non-melanoma). These two types are highly treatable and rarely fatal. Melanoma is the deadliest form of skin cancer. In order to protect yourself, limit sun exposure, wear sun screen and have any suspicious moles or skin irregularities checked by a doctor. Learn more about the causes, diagnosis and treatment of skin cancer here.