Indeed, Terasjarvi et al. did not find an association between TLR4 polymorphism and asthma risk alone, but instead between TLR4 polymorphism, H. influenzae colonization, and asthma risk (147), highlighting the need to consider multiple host-environment factors to unravel the complex and multifaceted nature of asthma. This evidence concerns the gene TLR4 and asthma.