Here we found that the concentration of IL4 late in an infection and of IL-13 throughout an infection, both produced by MLN, were associated with reduced worm burdens (Tables 3 and 4); and that, late in an infection the concentration of IL13 produced by the MLN and of RMCPII were associated with reduced per capita fecundity (Tables 6 and 7). The gene discussed is IL4; the disease is infection.