The National Institutes of Health (NIH) Exploratory/Developmental Grant (R21) funding opportunity supports the development of new research activities in categorical program areas. The R21 mechanism is intended to encourage exploratory and developmental research projects by providing support for the early and conceptual stages of these projects. These studies may involve considerable risk but may lead to a breakthrough in a particular area, or to the development of novel techniques, agents, methodologies, models, or applications that could have a major impact on a field of biomedical, behavioral, or clinical research.