Furthermore, to specifically facilitate visualization of lymphatic and endothelial vessels along with tumor–vessel interactions, we generated a transgenic nude mice model (ProxTom RFP Nu/Nu mice; Figure 3E), wherein the mice exhibited red, fluorescent lymphatics (tdTomato fluorophore under control of a Prox1 promoter, which encodes a transcription factor, prospero-related homeobox 1) necessary for the formation and maintenance of lymphatic vessels. Here, PROX1 is linked to neoplasm.