Anti-fms related receptor tyrosine kinase 4 antibodies are used for the immunodetection of the protein encoded by the FLT4 gene. In humans, the canonical protein has a reported length of 1363 amino acid residues and a mass of 152.8 kDa. Its subcellular localization is in the cell membrane, nucleus, and cytoplasm. Alternative splicing is reported to yield 3 different isoforms for this protein. It is notably expressed in endothelial cells. A member of the Tyr protein kinase protein family, it is reported to be a tyrosine-protein kinase that acts as a cell-surface receptor for VEGFC and VEGFD, and plays an essential role in adult lymphangiogenesis and in the development of the vascular network and the cardiovascular system during embryonic development. Other names for this target antigen include FLT41, LMPH1A, LMPHM1, PCL, VEGFR-3, VEGFR3, vascular endothelial growth factor receptor 3, and CHTD7. Gene orthologs have been identified in the mouse, rat, bovine, zebrafish, chimpanzee and chicken species.