Anti-C4.4A antibodies enable researchers to detect and measure the C4.4A antigen in biological samples. This target is a reported synonym of the LYPD3 gene, which encodes LY6/PLAUR domain containing 3. This protein is known to function in cell matrix adhesion, among other biological roles. The human version of C4.4A has a canonical amino acid length of 346 residues and a protein mass of 36 kilodaltons. It is reported to be localized in the cell membrane of cells and notably expressed in the tonsil, skin, oral mucosa, esophagus, and cervix. This target antigen may also be known as C4.4A.