Infectious virus produced from transfected 293T cells was quantified by endpoint dilution assay on Huh-7.5 cells (TCID50), which are highly permissive to flavivirus infection due to a dysfunctional RIG-I gene (Blight et al., 2002), based on LGTV-associated cytopathic effect (CPE). The gene discussed is RIGI; the disease is Flavivirus Infections.