METTL3 and Alzheimer disease: To determine the potential role of METTL3 downregulation and disturbed m6A regulation in neurodegeneration and pathogenesis of AD, we sought to knockdown the neuronal expression of METTL3 in vivo by using adeno-associated virus (AAV) containing vectors co-expressing enhanced green fluorescent protein (eGFP) and METTL3-targetting shRNA (shMettl3) and determine AD-related cognitive and pathological changes.