For the first time scientists have found that a growth factor called vascular endothelial growth factor receptor-3 (VEGFR-3), known to cause the growth of lymphatic vessels in the body, controls how immune cells traffic (move) within the eye and also stimulates the immune system to reject corneal transplants--the most common type of transplantation performed. The researchers from the Schepens Eye Research Institute and the Massachusetts Eye and Ear Infirmary, both affiliates of Harvard Medical School, have also found that when this growth factor is blocked, corneal transplants survive. The study, published in the August issue of Nature Medicine, is the first to make a link between VEGEFR-3 and the body’s immune response, and may hold significant promise not only for new treatments to prevent transplant rejection but also for diseases such as cancer that may proliferate because of VEGF-3.