The task of this study was to evaluate the impact of air pollution to gene expression in children and to analyze, if there is any specific effect to the origin and the development of asthma bronchiale. Specifically, we used gene expression profiles in leukocytes of asthmatic children compared with those in children without asthma, using Illumina HumanHT-12 BeadChip in a group of 200 children living in Ostrava–Radvanice/Bartovice (100 asthmatic and 100 healthy children, age 6–15 years) and a control group of 200 children living in Prachatice (100 asthmatic and 100 healthy children) (Libalova et al., 2011).