The investigators are investigating the early and late responses to allergen challenge. The research participants who the investigators will study (from three cohorts) will be part of independently-approved studies involving allergen challenge. Due to the uniqueness of the cohorts for novel genetic study, it is logical that the investigators should initially undertake hypothesis-generating experiments. The investigators will obtain blood samples from the participants, both pre-challenge and post-challenge. The investigators will determine gene expression and protein differences between these samples, and investigate if there are inherited genetic differences between individuals that may predict their specific responses to allergens.