Notably, neurons containing the phospho-epitope AT8 were seen in layer 5 of frontoparietal cortex, ventral hippocampal pyramidal, and amygdala neurons, whereas PHF-1-ir intraneuronal staining was seen only in the ventral hippocampus in perfusion-fixed 3-week-old 3xTg-AD mice. The gene discussed is PHF1; the disease is Alzheimer disease.