For instance, while AAV vectors were shown to persist in cardiac muscle for up to a year in some studies, their presence in skeletal muscle significantly diminished over time, likely due to promoter silencing or vector genome loss.30Ensuring long-term dystrophin expression across all affected tissues remains a critical challenge for the future development of CRISPR-based therapies for DMD. The gene discussed is DMD; the disease is Duchenne muscular dystrophy.