Most CD4+ T-cells in the blood, spleen, and MLN of control HIS-NSG mice expressed CC-chemokine receptor 4 (CCR4) without the presence of CCR5 and CXC-chemokine receptor 3 (CXCR3) (Figure 4A), which were indeed upregulated upon infection. The gene discussed is CXCR3; the disease is infection.