To elucidate the role of ICOSL/ICOS signaling in modulating the pattern of cytokine production in the ICOSL KO and WT C57BL/6 control strains, the mice were infected with S. japonicum (14±1 cercariae) and euthanized at 0 (before infection), 4 (early stage), 7 (acute stage), 12(chronic stage) or 16 (advanced stage) weeks post-infection. The gene discussed is ICOSLG; the disease is infection.