The molecule interleukin-7 (IL-7) is an important immune messenger protein which ensures that a sufficient number of T cells are present in our body for immune defence. Researchers from ETH Zurich have now demonstrated that IL-7 has another important function: it enhances the drainage function of lymphatic vessels, which collect fluid that has leaked out of blood vessels into the body tissue and return it to the bloodstream. In the future, this finding could become useful for lymphedema patients, whose lymphatic drainage system does not work properly, resulting in fluid accumulation and tissue swelling. The predisposition to develop lymphedema may,...