TLR3 and asthma: Interestingly, LPS also upregulated TLR3 expression in human monocytes, which was critical for antiviral responses.25 TLR3−/− mice infected with RV1B, however, displayed normal type I IFN responses, unchanged viral titres and reduced inflammatory responses.10 This is in marked contrast to our data generated in allergic TLR7−/− mice and previous data in non-allergic TLR7−/− mice.20 Further studies are now required to elucidate the clinical effect of endotoxins on TLR7-mediated responses in asthma.