A STAT report detailed the death of the first patient dosed with a brain‑penetrant viral gene therapy, triggering concern across labs and companies developing vectors engineered to cross the blood‑brain barrier. The patient died days after dosing from cerebral edema, an outcome not predicted by preclinical studies. The case, tied in reporting to work by Capsida Biotherapeutics and related brain‑targeting AAV programs, has prompted immediate safety reviews and raised questions about translatability of animal models for neuro‑directed gene delivery. Rare disease groups that had pinned hopes on these vectors are reassessing risk versus benefit ahead of further dosing. Regulators, funders and developers will likely demand additional safety data and conservative clinical‑stage designs for next‑generation brain‑penetrant delivery systems, potentially slowing an otherwise fast‑moving area of translational gene therapy.