Typically, only a small subset of peripheral Vδ2 T cells expresses the chemokine receptor CXCR4, but an increase in expression found in individuals with chronic infection raises the possibility that Vδ2 T cell may become susceptible to CXCR4-tropic viruses after initial infection (Imlach et al., 2003). This evidence concerns the gene CXCR4 and infection.