The 30 genes tested were selected according to their roles in biological processes associated to Tau protein and AD pathology (Mark1, Aatf, Pkn, Anp32a, Mapk1), neuronal networks and brain function (Grm5, Cacna1a, Ntrk2a, Ppp2r2b, Atxn1, Ctnn1), DNA Damage Response (Ercc3, Ten1, Xrcc4, Ctc1), transcription regulation and chromatin remodelling (Suv39h2, Suv420h1, Jarid2, Creb1, Cbfa2t2, Ppargc1a, Cnot4, Phf21a, Smarca1, Mtf2, Polr2a) or related with RNA-mediated gene silencing (Ddx6, Tnrc6b). This evidence concerns the gene XRCC4 and Alzheimer disease.