Then, in this dynamic and changing world, 3 distinct relationships between helminths and the human immune system can be recognized: One with chronic heavy parasite-load infections and mainly immunosuppressive, other of intermittent low parasite-load infections, predominantly IgE-enhancer and associated with urbanization; and a third, with absence of infections, where there is no parasite-derived immunoregulation. This evidence concerns the gene IGHE and infection.