Considering a basal model in which the age at LP, education, gender, MMSE, AD-related PET, and presence of ApoE4 were simultaneously considered, we obtained a prediction model in which the serial addition of pathological values of Aβ 42/40 and pTau was able to explain 82.1% of the variance in the Aβ 42/Ng ratio value. This evidence concerns the gene APOE and Alzheimer disease.