Spearman rank-order correlation of gene expression profiles across all three tissues determined by microarray platforms and TaqMan® Gene Expression Assay based real-time PCR. (A). Example gene expression profiles on 9 genes determined by Applied Biosystems microarrays, Agilent microarrays, and TaqMan Gene Expression Assay based real-time PCR. The gene expression profile for each gene across the three tissues was determined using the median expression level of the four technical replicates followed by a z-score transformation across the three tissues for each of platforms as described in Methods. (B). Distribution of the Spearman rank-order correlation coefficients (r) of profiles determined by each microarray platform vs. real-time PCR.