An earlier study performed in Rhesus Macaques administered an AAV9 variant (AAVhu68-CBh-SMN1) by IV route at 2 × 1014 vg/kg had also resulted in acute liver failure in 1/3 animals and transiently elevated transaminases that resolved without clinical sequelae in the remaining 2/3 of the animals.5 Altogether, these studies indicate an acute liver toxicity following IV administration of a high dose of AAV9-variant vector in different species of macaques. The gene discussed is SMN1; the disease is acute liver failure.