PTH controls calcium and phosphorus levels in the blood. PTH is made by the parathyroid glands, which are four pea-sized glands that lie behind the thyroid gland. If the blood calcium level is too low, the parathyroid glands release more PTH.
Skin cancer is a cancer of the cells in the outermost layer of skin, called the epidermis. The epidermis itself has three layers: an upper and middle layer made up of squamous cells, and a bottom layer made up of melanocytes and basal cells.
Types of Skin Cancer. Skin cancer is the uncontrolled growth of cancer cells in the skin. Left untreated, these cells can spread to other organs and tissues, such as lymph nodes and bone. Skin cancer is the most common cancer in the United States, affecting one in five Americans during their lifetimes, according to the Skin Cancer Foundation.