Lung and breast cancers are often treated with radiation, but repeated high doses can also harm healthy tissues in the lungs and heart. New research suggests that both organs can be protected during radiation with a drug called captopril, an ACE inhibitor that is commonly used to treat cardiovascular disease. Radiation causes fibrosis (excess connective tissue) in the heart, diminishing blood flow to—and so damaging—the lungs. However, captopril decreases fibrosis in irradiated hearts and, therefore, also protects the lungs in rats, researchers reported at the European Society for Radiotherapy and Oncology's 2013 forum. The researchers are now designing a clinical trial to see if captopril also protects against radiation damage in people.