Microarray methods provide global evaluation of changes in gene expression that the cell uses to adapt to different conditions. Given the rich legacy of biological knowledge available for Escherichia coli, the analysis of microarray data poses the challenge of comparing them against the knowledge available in the literature and against computational predictions. Here we present Gene Expression Tools (GETools), a computational environment to analyze expression profiles in Escherichia coliK-12, evaluating their congruence with characterized transcription units, upstream regulatory signals and putative transcriptional factors.