And an increasing body of evidence indicates that a balance between innate cells and CD4+ T helper (Th) cells Th1, Th2, Th17, and Treg responses (which cross-regulate one another during infection) rather than a polarizing effect (e.g., Th1 vs Th2) is likely beneficial in the development of protection against S. mansoni infections, both in humans and experimental models (58–61). This evidence concerns the gene CD4 and infection.