If cognition and dementia were considered as a continuum resulting from aging, relative to the APOE ε3ε3 genotype, the association of an APOE ε3ε4/ε4ε4 genotype with cognition or dementia was approximately equal to being older by 6.2 and 6.9 years, respectively, and a APOE ε2ε3 genotype was approximately equal to being younger by about 3.9 and 7.5 years of age, respectively (Figure 1C,F). The gene discussed is APOE; the disease is dementia.