An additional set of public gene expression data used to validate the coherence and predictive power of the biomarkers was obtained from hippocampus samples from elderly control and AD subjects, GSE1297 [31], [32]. These 31 samples were profiled using Affymetrix Human Genome U133A Array (HG-U133A). To select the probes and calculate the biomarker score, we matched the biomarker gene symbols to those represented on the array, refined them as described above, and averaged the gene expression values according to the equation in the previous subsection. The biomarker scores were then correlated with MMSE (MiniMental State Examination) as an available measure of AD severity.
