This Notice of Funding Opportunity (NOFO) is intended to support mechanistic research that aims to understand how and why expectancy effects occur in a cancer context, elucidate their role in cancer symptom management, and identify patients, symptoms, cancer sites, and contexts in which expectancy effects can be leveraged to improve cancer outcomes. Expectancies are defined in this context as beliefs about future outcomes, including ones response to cancer or cancer treatment. Expectancies can be evoked by social, psychological, environmental, and systemic factors. Expectancy effects are the cognitive, behavioral, and biological outcomes caused by expectancies. Expectancy effects can be generated by expectancies held by patients, clinicians, family members, caregivers, and/or dyadic/social networks. NCI is particularly interested in applications that enroll individuals and groups from populations historically underrepresented or excluded from biomedical and behavioral research.