Blood vessels are responsible for transportation of nutrients and oxygen throughout the whole body. Changes of oxygen level or metabolites lead to neovascularization, angiogenesis or vascular network trimming (also called vessel pruning) or regression, which are essential steps for establishing a functional and hierarchical mature vascular network to meet the needs of various organs. These processes are critical for tissue development and repair, as well as being associated with many diseases (e.g. bronchopulmonary dysplasia, pulmonary artery hypertension, ischemic cardiomyopathy, retinopathy and tumor growth). The long term goal of Pang's lab is to delineate the molecular mechanisms of these events under physiological and pathological conditions.