After JEV infection, EB leakage into the brain parenchyma significantly increased and reached the first peak at 2 dpi, when the Axl−/− mice showed significantly enhanced EB leakage compared with that observed in control mice, indicating that Axl deficiency promoted the BBB permeability at the early phase of infection (Fig. 3E and F, 2 dpi). The gene discussed is AXL; the disease is infection.