GAA and proximal spinal muscular atrophy: We have applied the MN assay in AAV9-based GT clinical trials, e.g., clinical trials of AAV9 expressing human acid alpha-glucosidase (GAA) gene therapy for patients with Pompe Disease (www.ClinicalTrials.gov ID NCT05567627, NCT05793307 and NCT06391736), and gene therapy drug GC101 in the treatment of spinal muscular atrophy (SMA) patients (www.ClinicalTrials.gov ID NCT05901987, NCT05824169 and NCT06421831).