To explore the role of endogenous production of nitric oxide in viral replication, islets isolated from DBA/2J mice (a strain that is susceptible to EMCV-induced diabetes (11, 12)) were treated with IL-1β and IFN-γ and then infected with 5 m.o.i. EMCV in the presence or absence of an iNOS inhibitor l-NMMA. The gene discussed is IL1B; the disease is diabetes mellitus.