PROJECT SUMMARY/ABSTRACT Pulmonary vascular disease (PVD) is a significant source of morbidity and mortality in neonates, infants and children with diverse heart, lung and systemic diseases. A major barrier to improving outcomes of children with PVD is the fundamental lack of understanding the differing pathobiologies among the spectrum of these disorders, which intersect between multiple clinical disciplines. This is compounded by the scarcity of training opportunities to develop and retain physician-scientists and scientists with expertise in PVD that allows for the successful translation of laboratory and clinical science across multiple disciplines. Thus, there is a need for well-trained scientists in Pediatric PVD who can perform collaborative and rigorous inter-disciplinary investigation to enhance the development of new treatment modalities. This novel application requests the resources to establish a unique two-year post-doctoral collaborative research training program in Pediatric PVD within the Departments of Pediatrics at the University of California, San Francisco, the University of Colorado, and Vanderbilt University. The goal of the program is to increase the number of highly trained, successfully funded and sustainable pediatric pulmonary vascular scientists, who will perform high level laboratory, clinical- translational, and/or health services research that will ultimately improve our understanding of the pathobiology of diverse pediatric PVD, design therapeutic plans that specifically target an individual’s underlying pathobiology, and thereby improve both short and long-term outcomes. To this end, this program aims to provide comprehensive scientific training through novel mentoring and collaborative approaches to enhance career development for physicians or post-doctorate scientists with an M.D., M.D./Ph.D. or Ph.D., who commit themselves to an academic career in pediatric PVD. The key and unique elements of this training program are: (1) a rich, diverse, mentored research experience; (2) interdisciplinary and inter-institutional experiences, including joint didactic learning opportunities, with direct integration into the North American Pediatric Pulmonary Hypertension Network and the associated Annual International Conference; and (3) continuous review and evaluation from academic leaders in the field. The centerpiece of the program for pediatric-scientists is the continuation of a 4-year fellowship training program (including but not limited to Pediatric Cardiology, Critical Care, Emergency Medicine, Neonatology, or Pulmonology), with 2 years devoted to intense research training in basic laboratory science, clinical-translational science, health services or epidemiology related to pediatric PVD. Exceptional faculty have committed their support as mentors, who lead and are affiliated with several of their universities’ research units and clinical programs, a represent a “critical mass” that few single centers can provide. Th...