 - There are unique combinations of environmental exposures cockroach allergens, indoor pollutants Environmental Tobacco Smoke ETS and Nitrogen Dioxide NO2, lack of microbial exposure, and family characteristics stress, genetic factors related to innate immunity that synergistically promote asthma onset, persistence, and morbidity in urban neighborhoods. These exposures and characteristics influence immune expression and lung development during critical periods of growth, resulting in specific asthma phenotypes. 