Researchers at ETH Zurich in Switzerland have discovered that a protein called IL-7 (a protein that regulates T-cells and is important in immune defense) could possibly be the answer to a treatment for lymphedema. Lymphedema is a condition that is caused by impaired lymphatic system function. Breast cancer treatment is the most common cause of lymphedema in the U.S. (tumor removal often damages lymph tissue and vessels), but it also has other causes, including parasite infection. Characterized by swelling in the extremities, currently there is no treatment or cure for lymphedema, and patients must rely on physical therapy and compression of the affected extremity to relieve symptoms. In mouse studies, mice with functioning IL-7 receptors were shown to have much better lymphatic drainage than mice that were modified to lack a functioning IL-7 receptor. Mice with increased production of IL-7 showed an increase in lymphatic drainage, and normal, healthy mice given the protein also showed an improvement in lymphatic drainage function. Researchers can now use these findings to develop new experiments to possibly create a treatment with IL-7 that could either help prevent lymphedema or treat existing lymphedema. Is it is estimated that 140-250 million people are affected worldwide by lymphedema, so a potential for a new treatment is very encouraging. Even more encouraging is the fact that IL-7 is already being tested in clinical trials for other indications, so if further research shows promise, a treatment could be closer than you might think!