Single platform co-expression dataset outperforms multiple platform co-expression dataset. The more cohesive GEO/GNF set containing a single microarray platform per species outperforms the more inclusive multi-platform Stuart et al. set (p < 10-10). Both sets have similar coverage, with 3212 and 3286 disease gene pairs for the Stuart et al. and GEO/GNF sets respectively. These results are based on co-expression data from human, fly, worm and yeast, with co-expression scores are averaged across species wherever possible. A) Disease gene rank histogram. B) Cumulative proportion of disease genes detected as the co-expression rank threshold is decreased from 1 to 0.