While a Poisson mixed model explaining the number of annual CF exacerbations with just log IgE showed no effect of log IgE (p = 0.2263), the model including atopy showed that in the presence of atopy based on positive serum allergen panels, as log IgE increases the exacerbation events increase (p = 0.0222) Fig. 5. This evidence concerns the gene IGHE and cystic fibrosis.