Thus, the influence of the ApoE4 haplotype on thepresence of mLOY in dorsolateral prefrontal cortex cells wasrevealed (Graham et al., 2019), and in a study using neuronsobtained from induced pluripotent stem cells from a patientwith familial AD with a mutation in the PSEN1 gene, it wasdemonstrated that LOY enhances the toxic effects of Aβ42,leading to impared neuron differentiation and premature celldeath (Mendivil-Perez et al., 2019). Here, PSEN1 is linked to Alzheimer disease.