Mini Review ; There is yet much to learn about the actions and role of CT. It will be important to better understand die physicochemistry of CT-CTR interaction, and the pharmacokinetics of CT, so that small molecule CT-mimetics and more potent, differently delivered, longer acting forms of the molecule can be designed to control bone resorption and turnover. It is important to understand the actions of CT in inflammation and stress, in the CNS, in blastocyst implantation and development, in cancer and in cell growth and morphogenesis, which could well have interesting and unexpected consequences. The recent recognition that the CTR can also interact with other peptides by collaborating with RAMPs, provides additional complexity to CT physiology. The study of CT in, as well as beyond its role as a calcium-regulating and bone-sparing hormone, will continue to provide insights of biological interest and of importance in our understanding of health and disease. © 2004 Taylor & Francis Ltd. ; David M. Findlay and Patrick M. Sexton