Study reveals how lung alveolus forms at cellular level Researchers from Children's Hospital of Philadelphia (CHOP) have determined what happens at a cellular level as the lung alveolus forms and allows newborns to breathe air. Understanding this process gives researchers a better sense of how to develop therapies and potentially regenerate this critical tissue in the event of injury. The findings were published online today by the journal Science. The lung develops during both embryonic and postnatal stages, during which lung tissue forms and a variety of cell types perform specific roles. During the transition from embryo to newborn is when the alveolar region of the lung refines its primary function of exchanging gas, which includes the critical process of ridding the body of carbon dioxide.