This Funding Opportunity Announcement (FOA) invites applications to enhance the pool of highly trained investigators from diverse backgrounds, including those from groups underrepresented in research areas of interest to the NHLBI. The career development will take place under the guidance of an experienced mentor in the biomedical, behavioral or clinical sciences leading to research independence. It is targeted toward individuals whose basic, clinical, and translational research interests are grounded in the advanced methods and experimental approaches needed to solve problems related to cardiovascular, pulmonary, and hematologic diseases and sleep disorders in the general and health disparities populations. This FOA invites applications from institutions with eligible faculty members to undertake special study and supervised research under a mentor who is an accomplished investigator in the research area proposed and has experience in developing independent investigators. This FOA is designed specifically for candidates proposing to serve as the lead investigator of an independent clinical trial, a clinical trial feasibility study, or a separate ancillary clinical trial, as part of their research and career development. Applicants not planning an independent clinical trial, or proposing to gain research experience in a clinical trial led by another investigator, must apply to the companion FOA (see RFA-HL-22-011).