To evaluate the reliability of the expression microarrays, expression levels of five genes were validated by quantitative real-time PCR using a Taqman approach (Applied Biosystems, Foster City, CA): CD63 (catalog# Hs01041237_g1), LPPR1 (catalog# Hs00214827_m1), PLK2 (catalog# Hs01573405_g), AKR1A1 (catalog #Hs00895477_m1) and MAPT (catalog #Hs00902194_m1). The expression of these genes was normalized using two reference genes as endogenous controls: POLR2A (catalog #Hs00172187) and RPS17 (Hs #00734303-g). The efficiencies of the target and reference genes expression were assessed by LinRegPCR software (http://www.gene-quantification.com/LinRegPCR_help_manual_v11.0.pdf). The expression levels of the five genes measured by the two platforms were well correlated (S1 Fig). The individual expression values reported in S10 Table also demonstrate an agreement in magnitude and direction of expression between the microarray and PCR based results.
