Anti-CD9 antibodies are immunodetection reagents used for the measurement of the protein encoded by the gene 'CD9 molecule' in humans, which may also be known as BTCC-1, DRAP-27, MIC3, MRP-1, CD9 antigen, and 5H9 antigen. Structurally, the protein is reported to be 25.4 kilodaltons in mass. Based on gene name, canine, porcine, monkey, mouse, and rat orthologs may also be found.