Through this Notice of Funding Opportunity (NOFO), the National Cancer Institute (NCI) intends to provide the infrastructure for early-phase cancer prevention clinical trials through the Cancer Prevention Clinical Trials Network (CP-CTNet), DCP's main mechanism for early clinical development of cancer preventive interventions. The phase 0-2 trials performed through CP-CTNet evaluate biologic effects of interventions and determine clinically relevant correlates, with the ultimate goal of advancing their further development for cancer prevention. The research network will develop multiple cancer prevention clinical trials targeting cancers arising in various organ sites, including collaborative studies across the Network, using the UG1 cooperative agreement funding mechanisms. This NOFO relates to the performance sites that will plan and perform clinical trials.