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.
The vast majority of skin cancers are basal cell carcinomas and squamous cells carcinomas. While malignant, these are unlikely to spread to other parts of the body. They may be locally disfiguring if not treated early. A small but significant number of skin cancers are malignant melanomas.