The protein encoded by this gene is a member of the parathyroid hormone family. This hormone regulates endochondral bone development and epithelial-mesenchymal interactions during the formation of the mammary glands and teeth. This hormone is involved in lactation possibly by regulating the mobilization and transfer of calcium to the milk. The receptor of this hormone, PTHR1, is responsible for most cases of humoral hypercalcemia of malignancy. Four alternatively spliced transcript variants encoding two distinct isoforms have been observed. There is also evidence for alternative translation initiation from non-AUG (CUG and GUG) start sites, in-frame and downstream of the initiator AUG codon, to give rise to nuclear forms of this hormone.