Similarly, more severe AD-associated effects of the ε4 variant of the APOE gene, the largest known genetic risk factor for sporadic AD, reported for females [12] cannot account for the entire range of phenotypic differences in the disease between the genders, because cognitive impairment progresses faster in women than in men even when considering only individuals without APOE ε4 alleles [13]. This evidence concerns the gene APOE and Cognitive impairment.