Parathyroid Hormone-like related Protein (PTHrP) is a member of the Parathyroid hormone family that is expressed in the mammary gland. It is known as a potent inhibitor of chondrocyte maturation. PTHrP is expressed by periarticular perichondrial cells and exerts its biological activity on PP-R expressing cells. During endochondral bone development PTHrP plays a major role in suppressing the onset of hypertrophic differentiation. It is also responsible for most cases of humoral hypercalcemia of malignancy. The antibody recognizes ~9.8 kDa of human PTHrP protein.