Anti-A33 antibodies are used in antigen-specific immunodetection in biological samples. The target A33 is a known alias name of the protein glycoprotein A33, encoded by the GPA33 gene in humans. This 319-amino acid residue protein is believed to play a role in cell-cell recognition and signaling. It is localized to the membrane of the cell and features N-glycosylated and palmitoylated post-translational modifications. In terms of tissue expression, it is reported to be expressed in normal gastrointestinal epithelium and in 95% of colon cancers. Other synonyms for A33 include cell surface A33 antigen and glycoprotein A33 (transmembrane).