Gene Expression Omnibus (GEO) is a public repository for gene expression data. While the amount of data in GEO has grown exponentially, the number of publications citing GEO has only grown linearly. The difficulty in data reuse is the mapping of probes in GEO datasets to established gene identifiers, which can change as annotations for the underlying sequences change. Therefore, microarray results need to be reevaluated with the latest probe annotations. There have been several previous efforts to reannotate microarray probe identifiers but only for a few platforms and species.
We built a fully automated system, Array Information Library Universal Navigator (AILUN), to reannotate all types of microarrays in GEO periodically by relating every probe identifier to Entrez Gene identifiers.