The lymphatic vasculature forms a second circulatory system that drains extracellular fluid from the tissues and provides an exclusive environment in which immune cells can encounter and respond to foreign antigen. Recently a number of interesting molecules have been identified that may be exploited as markers for lymphatic endothelium, including the hyaluronan receptor LYVE1, PALE, VEGFR3, podoplanin. LYVE1 has been identified as a major receptor for HA (extracellular matrix glycosaminoglyca