A selection of GEO screenshots from a typical experiment (GEO DataSet GDS877; 16). (A) DataSet record includes experiment summary information, DataSet subset classifications, and access to data mining features such as hierarchical cluster heat map and ‘Query subset A versus B’ tool. (B) DataSet hierarchical cluster heat map calculated by un-centered correlation coefficient/average linkage option. Regions of interest can be selected using the red image cropper box, then either expanded to view sample and gene annotation, downloaded, charted as line plots, or linked directly to corresponding Entrez GEO profiles records. (C) GEO profiles retrieval results; each entity includes sequence identifier and DataSet information, and a thumbnail profile image. (D) Expanded profile chart depicts expression value information for the crystallin gene across each sample in DataSet GDS877. Experimental subset groupings are reflected in labels at foot of chart.