Podoplanin is a mucin-type 1 transmembrane glycoprotein found in a wide range of tissues. It appears to be differentially expressed in endothelial cells of lymphatic but not blood vessel origin. In normal skin and kidney, podoplanin co-localizes with VEGFR3/FLT4, another marker for lymphatic endothelial cells. It appears to be involved in lymphangioigenesis and cell migration and is regulated by the lymphatic-specific homeobox gene Prox1. Podoplanin has also been found to be expressed on a wide variety of tumors.