METTL3 and Alzheimer disease: The brains of Mettl3−/− mice and Ythdf1−/− mice showed cognitive impairment similar to AD, in which the brains of Mettl3−/− mice showed microglia activation, and METTL3 overexpression mice prevented AβO-induced synaptic loss and cognitive impairment (Shi et al., 2018; Zhao et al., 2021).