APOE and Alzheimer disease: The model, including both PGSz and APOE ε4, in essence separating out the effects of APOE ε4 carrier status and the remainder of the PGSz signal, was also significant (χ2[3] = 77.26, p < 0.001), explaining 10.6% of variance and correctly classifying 64.4% of participants as AD or CN.