In this clinical study (Figure 2D) we found that AD patients with mild (2467 fg/mL) and moderate (2647 fg/mL) dementia had significantly higher levels of Aβo compared to healthy controls (1538 fg/mL), p<0.01 and p<0.001 respectively, while AD patients with severe dementia (1250 fg/mL) did not significantly differ from the control group (Figure 2d). This evidence concerns the gene ABO and Alzheimer disease.