Anti-SRY-box transcription factor 18 antibodies are used for the immunodetection of the protein encoded by the SOX18 gene. In humans, the canonical protein has a reported length of 384 amino acid residues and a mass of 40.9 kDa. Its subcellular localization is in the nucleus. It is notably expressed in fetal lung, placenta, skeletal muscle, liver, kidney, spleen, prostate, ovary, msosmall intestine and colon. It is reported to be a transcriptional activator that binds to the consensus sequence 5'-AACAAAG-3' in the promoter of target genes and plays an essential role in embryonic cardiovascular development and lymphangiogenesis. The gene encoding this protein is implicated in Hypotrichosis-lymphedema-telangiectasia syndrome. Other names for this target antigen include HLTS, transcription factor SOX-18, SRY (sex determining region Y)-box 18, SRY-box 18, and HLTRS. Gene orthologs have been identified in the mouse, rat, bovine, frog, chimpanzee and chicken species.