In order to evaluate the effect of using distinct promoter sequences in the efficacy of gene therapy, 2 week-old G6pc-/- mice were infused intravenously with AAV8-G6pc carrying the canine G6pc promoter (instead of the CMV/CB promoter); in these mice, a complete correction of growth retardation and a partial correction of fasting hypoglycemia, significant reduction in liver glycogen content, a normalization of blood cholesterol levels, a restoration of liver G6Pase activity to 25% of normal, and a prolonged survival (up to 7 months) were observed in treated mice [123]. The gene discussed is G6PC1; the disease is Hypoglycemia.