The 5q31 locus is an example of a common locus for the susceptibility to helminthic infection and allergic diseases, as shown by the linkage with the susceptibility to S. mansoni and the genetic associations between IL13 polymorphisms with the immune response to O. volvulus, implicating a coding variant (Arg110Gln) that has been previously associated with asthma and other allergies [477, 478]. The gene discussed is IL13; the disease is allergic disease.