The 5E8-G9-B4 monoclonal antibody specifically reacts with human CD193, also known as CKR3 and CCR3. CD193. CD193 is a G protein-coupled seven transmembrane receptor that binds to eotaxin-1,2,3 and to a lesser degree to MCP-3,4 and RANTES. It is expressed on eosinophils and basophils, mast cells platelets, CD34+ hematopoietic progenitor, and mononuclear phagocytes. CD193 plays a role in asthma and is a co-receptor for HIV-1,2.