For many years my research has focused on the function and mechanism of action of the secreted phosphoprotein osteopontin, which has roles in cancer biology, immunology and bone biology, and has led my work into these different but overlapping fields. I am considered an expert in the field of osteopontin, regularly participate in organizing meetings focused on this protein, and have authored numerous reviews on this topic. My current research focus is on the role of osteopontin and its receptors (a series of integrins) in regulation of the innate immune response to endodontic infection. Specifically, we are focused on the role of osteopontin in the regulation of neutrophil chemotaxis, and have described a novel role in the regulation of CXCR2 function, internalization and trafficking. Since migration of immune and tumor cells underlie many forms of pathology associated with elevated OPN expression, these studies may have wide implications for the role of osteopontin in these diseases, including metastatic disease.