Asthma prevalence has been on the increase, especially in North America compared with
other continents. However, the prevalence of asthma differs worldwide, and in many
countries the prevalence is stable or decreasing. This highlights the influence of
environmental exposures, such as allergens, air pollution, and the environmental
microbiome, on disease etiology and pathogenesis. The epigenome might provide the
unifying mechanism that translates the influence of environmental exposures to changes in …