Constitutively active, ligand-independent G protein-coupled receptor that has immunoevasive and oncogenic activities (PubMed:34216564, PubMed:15596846, PubMed:15596837, PubMed:30647152). Couples with the host inhibitory G protein (Gi) in order to disrupt the host chemokine signaling (PubMed:34216564). As a consequence of its constitutive activity, mediates host CXCR4 inhibition (PubMed:20622011). Enhances degradation of host major histocompatibility complex class I antigens via lysosomes, thereby modulating the antigen presentation to cytotoxic T cells (PubMed:19119421, PubMed:21123379, PubMed:23315076). Targets selectively HLA-A, HLA-Band HLA-E molecules (PubMed:23315076). Targets also newly synthesized MHC-I/peptide complexes en route to the host cell surface (PubMed:21123379). Inhibits the host EIF2AK2/PKR phosphorylation (PubMed:15596837). Displays tranforming activity (PubMed:20543866). Interacts with host CXCR4 to form higher-order heterooligomers (PubMed:20622011). Interacts with host Gi heterotrimer (PubMed:34216564). Expressed early in the viral lytic cycle. The extracellular N-terminus and third extracellular loop are involved in host MHC-I down-regulation (PubMed:30647152). The cytoplasmic C-terminus is also required for host MHC-I down-regulation (PubMed:23315076). Belongs to the Epstein-Barr virus BILF1 protein family. Extended N-terminus. Extended N-terminus. Extended N-terminus. Extended N-terminus. Extended N-terminus. Extended N-terminus. Extended N-terminus. Extended N-terminus.