TLR4 and pneumococcal meningitis: Studies in mice with targeted deletion of TLR receptors have shown the importance of both TLR2 and TLR4 in driving the pathogenesis of pneumococcal meningitis, in that the blockade of TLR2 and/or TLR2/4 signalling resulted in impaired host bacterial clearance, aggravated clinical signs and graver neurological complications11–14.