MME and Alzheimer disease: In summary, we demonstrated that combinational treatments of NSCs encoding the ChAT gene, an ACh-synthesizing enzyme, and microglial cells encoding the NEP gene, an Aβ-degrading enzyme, or SRA gene, an Aβ-uptaking receptor exerted complete restoration of learning and memory functions by eliminating Aβ accumulation and recovering ACh level in AF64A-challenged AD model mice.