This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The purpose of this study is to determine what influences allergy and asthma, a breathing disorder caused by inflammation in the breathing tubes of the lungs. This study is being done because we are interested in the genetics of allergy and asthma how asthma and allergy may be passed down in families through generations. Asthma and allergy are inflammatory diseases, and we are interested in how certain chemicals that regulate this inflammation are genetically controlled. One such chemical is named "ICOS" that is made on the surface of a cell in your blood, called "T lymphocytes" or simply "T cells"-. ICOS helps to control how these T cells respond to inflammation. We have found there are genetic differences in the on/off switch for the ICOS gene (a piece of DNA that has the code to make ICOS) in certain individuals and the genetic differences are associated with the predisposition to allergy. The major hypothesis is that people have genetic differences in the ICOS gene and these differences influence the chemicals their T cells make. As a result they are predisposed to asthma and allergy. We will be studying adults, ages 18 to 54, with allergy and asthma compared to people without either condition. The major questions that are being asked in this research study are 1) how do genetic differences in the on/off switch for ICOS change how much of this chemical is made in T cells, and 2) do these genetic differences change the way that the T cells work in people with allergy and asthma?