NOS2 and schistosomiasis: However, more than a 2-fold higher iNOS expression was noted in S. japonicum-infected WT mice as compared with that of uninfected WT control mice (Fig. 4B), confirming that hepatic granuloma formation in acute schistosomiasis is predominantly mediated by a Th1-based immune response rather than a Th2-related immunity in WT mice.