GAA and Glycogen storage disease due to acid maltase deficiency: Previously, our laboratory generated a Gaa knockout (KO) (Gaa−/−) mouse model that has a complete GAA deficiency, resulting in tissue pathology and symptoms indicative of classic infantile Pompe disease.56, 57, 58 Using this mouse model, we demonstrated that HSPC-mediated lentiviral gene therapy with human GAA resulted in increased GAA enzyme activity in host tissues, reduction of glycogen accumulation, and improved cardiac and motor function.59