Next, to find if neuronal LAL impacts Aβ pathology and cognitive function in vivo, 3xTg‐AD mice were given either PHP.eB.syn.shLAL or PHP.eB.syn.LAL.WPRE viruses that cross the mouse blood–brain barrier (BBB)60 to either knock down or over express LAL, respectively. Here, LIPA is linked to Alzheimer disease.