This rabbit monoclonal CD99 antibody, a 32 kDa T-Cell surface glycoprotein, is also known as MIC2, E2 and 12E7, HuLy-m6 or FMC29. This antigen is expressed on the cell membrane of some lymphocytes, cortical thymocytes, and granulosa cells of the ovary. CD99 is also expressed by most pancreatic islet cells, Sertoli cells of the testis and some endothelial cells. Mature granulocytes express limited or no CD99. Studies have shown that CD99 may be a sensitive marker for Ewing’s sarcoma and peripheral neuroectodermal tumors and may aid in the differential diagnosis of small blue cell tumors.