ur overall objective is to persuade the reader that social psychological theory can play a critical role in improving the understanding of the behavioral issues 0 surrounding detection, control, treatment, and recovery from cancers. In addition, we hope to make the following, more specific points. First, we believe that the relationship between behavioral research on cancer and "basic" psychological theory is a two-way street, in which each side informs and influences the other. Thus, we do not believe that behavioral research on cancer is merely an applied endeavor in which investigators use "basic" psychological theory to understand behaviors related to cancer. Rather, we believe that behavioral research in the cancer domain makes important contributions to basic, psychological theory.Second, we argue that a multilevel self-regulation model is needed for the science of modeling and the practice of influencing behaviors in the cancer domain. A fully specified, self-regulation model of this type will capture people's perceptions of cancer ( e g , its perceived symptoms, causes, consequences, time frames, control) and their perceptions of the procedures for controlling the threat of cancer, and it will conceptualize the relationships of these perceptions to the individual's personal and sociocultural context. We propose further that sociocultural variables and personal characteristics are contextual factors or moderators whose primary effects on behavior are through their influence on the perception of disease threats and the procedures used for threat management (Leventhal, Diefenbach, & Leventhal, 1992; Leventhal, Leventhal, & Cameron, in press), although we do not rule out the We thank Andrew Baum for his encouragement and helpful comments. The work was supported by Grants AG12072 and AGO3501 from the National Institute on Aging.