CD4 and asthma: Indeed, Schistosoma‐associated CD4+CD25highFOXP3+ Tregs have been found to exert a suppressive effect on both T cell proliferation and cytokine production.28 Such regulatory responses are thought to function to suppress both Th1‐ and Th2‐mediated inflammation in the host, and thus, the development of asthma and allergy.