In 2007, the SAPALDIA investigators had reported in the New England Journal of Medicine that improvements in air quality, measured as PM10, had attenuated the age-related lung function decline. The new report published in the Journal “Environmental Health Perspectives” presents evidence that the benefit from improved air quality depends on genetic background. Common variants in three cell cycle control reduction genes (CCND1, p53 and p21) modified the association between lung function decline and PM10 exposure. The results are intriguing as they provide first epidemiologic proof that genes involved in cancer biology might also play a role in the mechanism by which air pollutants affect respiratory health. For example, SAPALDIA participants carrying the genetic variant not associated with increased cancer risk benefit most from an improvement in PM10 exposure. They experience the most pronounced attenuation of age-related lung function decline. The observed differences in lung function decline between genotypes were comparable to the effects of smoking a pack of cigarettes per day. This report gives a novel perspective to protecting subjects most susceptible from harmful levels of air pollutants, as legally required in Switzerland.