PROJECT SUMMARY/ABSTRACT Candidate: Dr. Lisandra Via Ellis is a physician with extensive training in vascular biology and lung development. She is a postdoctoral fellow at MD Anderson Cancer Center seeking to understand how blood vessels develop in the lung and how this process is affected in disease. She just published her first, first-author paper in Developmental Cell. Career development: Dr. Vila Ellis' mentors include Dr. Jichao Chen, a successful scientist who studies developmental biology in the mouse lung, and Dr. Burton Dickey, a physician who has over 30 years of research experience in the lung. Additionally, Dr. Vila Ellis will have the support of many collaborators in the field, as well as a mentoring committee to ensure she meets the expected milestones of this proposal, and guarantee a smooth transition to an independent career. Research: Dr. Vila Ellis' work has shown that Vascular endothelial growth factor A (Vegfa) specifies a novel population of endothelial cells in the lung. These cells are transcriptionally and morphologically distinct, and in their absence the alveolar space is aberrantly enlarged, reminiscent of bronchopulmonary dysplasia. In the future, Dr. Vila Ellis will study how this specification process happens and what role these new cells play in lung disease. In summary, this proposal will address the mechanisms of pulmonary endothelial cell heterogeneity and help establish the lung endothelium as a key component in the origin of developmental diseases.