APOE and Alzheimer disease: In the case of the APOE-ε4 gene, which is known as a genetic risk factor regarding AD (35, 36), we exhibited the distribution of (αi)1 ≤ i ≤ I and (τi)1 ≤ i ≤ I for the subpopulations defined by the number of alleles of the gene as shown on Figure 11.