Parathyroid hormone-related protein (PTHrP) is a neuroendocrine peptide which is a critical regulator of cellular and organ growth, development,Mouse,igration, differentiation and survival and is involved in epithelial calcium ion transport. PTHrP regulates endochondral bone development and epithelial-mesenchymal interactions during the formation of the mammary glands and teeth. Defects in PTHrP are the cause of brachydactyly type E2 (BDE2). BDE2 is a form of brachydactyly. Brachydactyly defines a group of inherited malformations characterized by shortening of the digits due to abnormal development of the phalanges and/or the metacarpals.