IL4 and helminthiasis: In helminth infections, immune response is often dominated by the production of T helper type 2 (Th2) immune cytokines, such as interleukin-4 (IL-4), IL-5 and IL-13, which represent a critical immune response against helminths invading cutaneous or mucosal sites, such as A. abstrusus; these also may play a role in reducing the severity of acute illness.