Our findings suggest that the progression of childhood asthma is linked to altered regulation of inflammatory pathways, a distinctive pattern of altered gene expression associated with structural remodelling in the airway wall, and increased expression of both interleukin 4 (IL-4; encoded by Il4) and interferon-γ (IFN-γ; encoded by Ifng) by CD4+ T cells. This evidence concerns the gene IFNG and childhood onset asthma.