A recent very carefully conducted study in 44 adult patients with dengue fever DF and 18 patients with DHF has showed that cytokines such as IFNγ, IL-17, IL-4, IL-1β and vascular endothelial growth factor (VEGF) were significantly higher in patients with DF when compared to those with DHF in the febrile phase [10]. This evidence concerns the gene IL4 and dengue disease.