CXCL9 and viral infectious disease: During viral infections, γδ T cells can get activated by cytokines like TNF-α, IL-1, IL-6, and IL-18 produced by other immune cells52 and upregulate the chemokine receptors such as CXCR3 and CCR5, enabling their recruitment to the site of inflammation, rich in CXCL9/10/11 and CCL3/4/5.