The major focus in my lab is the origin and development of mammary cancer in the mouse. To explore the early development of these cancers, we are analyzing the stem cell origin of carcinogen-induced mammary tumors, and the role of progesterone in enhancing tumorigenesis. We are also very interested in the process of metastasis of these cancers and have developed a series of transformed cell lines that form bone metastases in syngeneic mice. The two-way mechanisms of tumor- host interaction in these metastases is an area of major focus, especially in the bone microenvironment. Finally, we have a long-standing interest in the molecular mechanisms of osteopontin function, particularly in metastasis and bone resorption.