Asthma-Causing Molecule Is Found

Researchers have identified a molecule that plays a key role in causing asthma symptoms, a finding that could lead to new treatments for the disorder that affects 15 million Americans. Researchers at Johns Hopkins University and Hospital in Baltimore and UC San Francisco--experimenting independently with mice--have found that a reaction triggered by a molecule called interleukin-13 was a primary cause of symptoms--inflammation, clogging and restricted air flow that cause breathing problems in asthma attacks.