Interestingly, one study has revealed that, by injecting a lentivirus-packaged miR-31 overexpression plasmid into the hippocampus of AD mice, the expression of App and Bace1 are declined, which finally reduces Aβ deposition and improves cognitive ability (Barros-Viegas et al., 2020). The gene discussed is BACE1; the disease is Alzheimer disease.