Taken together, these observations indicate that the impairment of IL-4Rα-mediated signaling, but not the Cre transgene expression, specifically within the Foxp3+ Treg cell compartment during experimental schistosomiasis drives a poor accumulation of Foxp3+ T cells in the inflamed tissues and consequently results in elevated host fibrogranulomatous responses around the trapped parasite eggs. The gene discussed is FOXP3; the disease is schistosomiasis.