Outline of the experimental procedure. RNA expression profiles were generated using cDNA and oligo microarrays, and protein expression levels were generated using immunohistochemical staining of cell microarrays with antibodies from the Human Protein Atlas initiative. The expression levels were measured in each assay in each of the 23 cell lines. For each of the 1066 gene products for which data were obtained from all three platforms, the Spearman correlation coefficients between the RNA oligo-protein, RNA cDNA-protein and RNA oligo-RNA cDNA datasets were calculated. The equation of the Spearman correlation calculation is shown in the Figure.