Most significantly, DYRK1A overexpression is also observed in sporadic AD patients despite an euploid background, resulting in equivalent neuropathological manifestations as those seen in adult DS cases (Ferrer et al., 2005; Kimura et al., 2007), although the timing and localization of this imbalance can differ between these two conditions (Wegiel et al., 2008). Here, DYRK1A is linked to Alzheimer disease.