The role that inherited genetic variation might play in these differential early and late responses has so far been unexplored. However, recent experimental data in mouse models provide strong evidence that genetics could play an important role. When a specific intracellular pathway is disrupted by specific mouse gene-knockouts, this leads to the inhibition of a late response to allergen challenge, whilst maintaining the early response. The pathway is known as the Bcl10/Malt1 pathway, and it normally responds to allergen exposure by activating the expression of genes that code for pro-inflammatory proteins. The uncoupling of the late response from the early response suggests a possibility that genetic variation in genes involved in the human Bcl10/Malt1 pathway may influence the nature of the allergic response in humans. We will investigate whether there is a genetic basis for why some individuals develop an isolated early-phase response after allergen challenge whilst other individuals develop early- and late-phase responses (dual response).