DNMT1 and Alzheimer disease: Mastroeni et al. (2013) showed that DNA methyltransferase 1 (DNMT1) and Pol II were abnormally sequestered in the cytoplasm of CA1 hippocampal neurons from AD patients, and were able to recapitulate this effect in human SK-N-Be(2) neuroblastoma cells exposed to toxic Aβ oligomers for 36 h.