RecruitingStudy of the Effect of Innate on the Inflammatory Response to EndotoxinBackground: \- Innate immunity is the process by which white blood cells and other parts of the immune system sense and respond to potential infections by causing an inflammation. Researchers are interested in studying how the body responds to certain environmental factors, and whether the body s response can contribute to chronic illnesses or diseases such as asthma and certain types of cancers. Objectives: \- To examine how specific genes and proteins in blood cells respond to environmental exposures. Eligibility: \- Healthy volunteers between 18 and 45 years of age. Design: * The study will involve one visit of 45 to 60 minutes. * Participants will be screened with a brief physical examination and finger stick to determine if they are eligible to donate blood for the study, and will complete a questionnaire about any medications or other drugs (e.g., cigarettes) they may be taking. * Participants will provide a blood sample for research purposes.