However, they expressed five chemokine receptors: CCR4 (46, 47), CXCR1/CXCR2 (48), CCR6 (49), and CXCR4 (50), which direct the movement of circulating T cells to sites of tissue injury, infection, inflammation, and under physiological conditions to the skin (46, 47) (Figure 4). This evidence concerns the gene CXCR4 and infection.