Living in highly polluted cities (high PM and ozone) is also associated with hypermethylation of FOXP3 in regulatory T cells (Nadeau et al. 2010), while neonates who were prenatally exposed to polyaromatic hydrocarbon (PAH) had hypermethylated ACSL3 in DNA of umbilical cord white blood cells (Perera et al. 2009); notably, both of these genes are involved in asthma pathogenesis. This evidence concerns the gene FOXP3 and asthma.