Idiopathic pulmonary fibrosis slowly turns the lungs stiff and scarred, but researchers may have found why the damage keeps building. Their work points to a survival signal inside key cells, and to a treatment approach that could help the lungs recover. Every breath depends on millions of tiny air sacs inside the lungs working smoothly. In people with idiopathic pulmonary fibrosis, or IPF, that delicate system slowly breaks down. Healthy lung tissue becomes stiff and scarred. Oxygen struggles to move into the bloodstream. Even simple activities can leave patients exhausted and gasping for air. Doctors have long known that scar-forming cells called fibroblasts play a major role in the disease. These cells normally help repair injured tissue. Once healing is complete, many fibroblasts die through a natural process called apoptosis, which acts like the body’s cleanup system. In pulmonary fibrosis, that process fails. A new study from researchers at National Jewish Health and collaborating institutions may finally explain why. The research, published in Nature Communications, found that a protein called BCL-2 helps harmful fibroblasts avoid …