Chief cells are the cells which form parathyroid glands and have a role in the synthesis and release of parathyroid hormone (PTH). Parathyroid glands are endocrine glands located in the neck, more precisely located on the back of the thyroid gland. The hormone of this gland is parathyroid hormone and together with calcitonin (a hormone made by the thyroid gland) have key roles in regulating the amount of calcium in the blood and within the bones.