Two other studies related SNPs in the gene coding for GSTP1 and exposure to dampness [(20), p. e30694] and air pollution [(21), p. e52715]; one study described complicated gene–gene and gene–environment interactions for dampness (but not several other exposures) and asthma [(20), p. e30694] while the second described a small increased risk for asthma among those genetically predisposed to oxidant stress and exposed to nitrogen dioxide (NO2) [(21), p. e52715]. Here, GSTP1 is linked to asthma.