Description: The MEM-166 monoclonal antibody reacts with human CD177, a 58-64 kDa GPI-anchored glycoprotein. The human CD177 locus codes for at least two alleles, NB1 and PRV-1, which differ by only 4 amino acids. CD177 is expressed on granulocytes, early erythroblasts, megakaryocytes, promyelocytes and myelocytes. CD177 mRNA levels are elevated in several different myeloproliferative disorders including polycythemia vera, and antibodies to CD177 are involved in neonatal alloimmune neutropenia, autoimmune drug inducedneutropenia, and graft failure following marrow transplantation.