Figure 3.

Cross-platform dataset matching revealed by EXALT. Heat-map illustrating the statistical significance among NCI-60 gene expression profiling experiments. The datasets include those reported by Staunton and coworkers [13] (dataset A), Butte and colleagues [12] (dataset B), Ross and coworkers [14] (dataset C), and GDS89. Datasets A and B were generated using Affymetrix arrays, whereas datasets C and GDS89 were generated using spotted cDNA arrays. Dataset comparisons exhibited adjusted mean P values below 0.01 (corresponding to values > 2.0 on the -log₁₀ scale). The greatest significance levels were observed for self-matching and matches between studies using the same microarray platform. EXALT, EXpression signature AnaLysis Tool; GDS, Gene Expression Omnibus dataset.