Test Details: CD200 is a member of the Immunoglobulin superfamily with 2 Ig domains, a transmembrane and cytoplasmic domain. CD200 is expressed on resting and activated B cells, a subset of resting and activated T cells, keratinocytes, peripheral and central nerve cells, follicular dendritic cells and ovarian cells. Myeloid cell regulation is the major function of CD200 molecule. CD200 is identified as a potentially useful antigen for flow cytometric immunophenotyping of lymphoid neoplasms, particularly those of the B lineage.