GAA and glycogen storage disease II: In addition, it is known that in Pompe disease autophagy is blocked, and that, as a result, GAA trafficking toward lysosomes is affected by impaired autophagy: a significant portion of the endocytosed enzyme was shown to be trapped in autophagic areas rather than reaching the lysosomes and clearing lysosomal glycogen accumulation.87, 88, 89, 90, 91 Fukuda and colleagues also showed impaired processing of the GAA protein in isolated muscle fibers, but not in total tissue homogenates.87