The single p63 or dual p63/D2-40 and p63/CD31 immunoreactivities in occasional lymphatic channels containing tumor emboli and the more negative immunoreactivities of D2-40/CD31/Prox-1/VEGFR-3 in the majority of vessels containing tumor emboli suggested the possibility that they represented immature and newly created vasculature derived from myoepithelial-lined ducts. The gene discussed is FLT4; the disease is neoplasm.