In the year 2000, the International Union of Pharmacology Committee on Receptor Nomenclature and Drug Classification (NC-IUPHAR2) approved a nomenclature system for chemokine receptors, the major seven transmembrane (7TM) receptors of the immune system, as recommended by the NC-IUPHAR Chemokine Receptor Subcommittee (Murphy et al., 2000). At that time, the chemokine receptor family consisted of 18 7TM proteins in humans, which were divided into four subfamilies based on chemokine subclass specificity. Two additional molecules, named Duffy and D6, which both have 7TM structure and bind chemokines but lack a known signaling function, were excluded from the nomenclature system, as were a group of functional 7TM chemokine receptors encoded by herpesviruses (Rosenkilde et al., 2001). The nomenclature system is logical, noncontroversial, and universally accepted and used (Table 1). Moreover, it has served as a template for the creation of a chemokine ligand nomenclature system (Zlotnik and Yoshie, 2000). Both systems have facilitated communication among immunologists and pharmacologists as these molecules have become important drug targets in immunologically mediated disease and HIV/acquired immunodeficiency syndrome. Since publication of the NC-IUPHAR document reporting the nomenclature system in the year 2000, one new receptor subtype, CXCR6, has been identified (Matloubian et al., 2000; Wilbanks et al., 2001), and one other subtype, CCR11, has been disqualified (Schweickart et al., 2000, 2001). Duffy and D6 remain as binding sites. The aim of the present article is to provide a brief update on these receptors.