The 2007 non-systematic review of gene–environment interactions for asthma [(16), p. 1032–1035] found that the majority of the literature had been published since 2000 and was focused in two areas: first, interactions between oxidant exposures (primarily SHS) and variants in genes coding for antioxidant defenses [especially the family of antioxidant enzymes collectively called glutathione-S transferase (GST)]; and second, interactions between exposures to bacteria or bacterial products and variants in genes coding for components of the adaptive and innate immune system (e.g., CD14). This evidence concerns the gene CD14 and asthma.