Context-based associations versus the metabolic network distance for the yeast metabolic network. (a) mRNA expression distance. The expression distance is calculated as 1-|correlation|, where correlation is the Spearman's rank correlation between genes' mRNA expression. Close neighbors in the metabolic network have similar expression profiles. (b) Gene fusion events (Rosetta Stone). The fraction of proteins involved in gene fusion events. The adjacent genes in the network are much more likely to form a Rosetta Stone protein. (c) Phylogenetic profiles. Pearson's correlations between phylogenetic profiles for genes close in the network are more likely to be similar. (d) Chromosomal distance between genes. The mean physical distances (in kilobase pairs (kbp)) between ORFs are shown. The adjacent genes in the network are significantly closer to each other on yeast chromosomes.