In some clinical trials involving DMD patients, the systemic delivery of the AAV9 vector carrying the human micro-dystrophin gene at high doses (5 × 1013 to 3 × 1014 vg/kg) is reported to cause serious adverse events, including cardiopulmonary insufficiency and thrombocytopenia [201], which might be responsible for the recently described patient death. The gene discussed is DMD; the disease is Thrombocytopenia.