Recent studies reveal that Dicer, which functions downstream of Drosha in miRNA biogenesis cascade, has a protective role in dopamine neurons (Chmielarz et al., 2017) and conditional knockout of Dicer results in tau hyperphosphorylation and neurodegeneration that resembles the pathological changes observed in AD (Hebert et al., 2010). Here, MAPT is linked to Alzheimer disease.