APOE and Alzheimer disease: In 2005, one study reported an AD polygenic score model constructed from nine cholesterol-related single nucleotide polymorphisms (SNPs) including APOE-ε4 that exhibited superior performance for classifying AD compared to APOE-ε4 alone [area under the receiver operating characteristic curve (AUC) = 0.74 vs. 0.66 for the polygenic score model and APOE-ε4, respectively] (Papassotiropoulos et al., 2005).