CD15 is an antigen present on myelomonocytic cells and Lacto-Nfucopentose III (also known as hapten X). It is present on greater than 90% of granulocytes including neutrophils and eosinophils, and to a lesser degree, on monocytes. CD15 is expressed in Reed-Sternberg cells of Hodgkins disease (of the nodular sclerosis, mixed cellularity and lymphocyte-depleted subtypes). This Antibody recognizes myeloid cells, mainly granulocytes but not on B cells, T cells, monocytes, erythrocytes or platelets. Positive staining for CD15 combined with a negative reaction for lymphocytic markers may provide support for Hodgkins disease. Fifty percent or more of adenocarcinomas have been described as showing significant cytoplasmic positivity for CD15. It does not detect most mesotheliomas.