There are currently very few tools for quantitative assessment of the lung and airway prior to surgery, radiation treatment, or other interventional approaches. Current tools focus on image analysis, usually based on densitometry or texture analysis. No tools are currently available for patient-specific prediction of respiratory system function post-treatment. Our virtual lung provides the capability to predict redistribution of air and blood flows and their impact on gas exchange and other physiological functions in response to various interventions or treatments. Our Flagship is developing the virtual lung as a clinical tool for treatment assessment in individual patients, first focusing on surgery of the nasal airway and acute pulmonary embolism.