In pathogen-associated molecular patterns (PAMP)-related research, studies using Japanese encephalitis virus (JEV) infection found that while TLR3-/- mice were highly susceptible to the infection, TLR4-/- mice showed enhanced resistance, displaying mild CNS inflammation characterized by reduced viral load, leukocyte infiltration, and pro-inflammatory cytokine expression (16). Here, TLR4 is linked to infection.