Du et al. 41 have found that APOE ɛ4 is associated with m6A ‘writers’ METTL3, METTL16, YTHDC2, RBMX, and LRPPRC in the AD brain, and APOE ɛ4+ AD mice present high levels of METTL342. Here, METTL3 is linked to Alzheimer disease.