The NCBI taxonomy as displayed by the BLASTGrabber matrix viewer. A) The taxonomic distribution for the two Fibronectin-3 and I-Set motifs as queried against the NCBI nr database, represented by the absolute number of hits per query/taxonomic unit. Heat map display mode has been chosen. Most taxonomic groups (such as “Deuterostomia” or “Nematoda”) are collapsed, as indicated by the “+” (expandable) sign. The “Amphimedon Queenslandica”, “Trichoplax adhaerens” and “Capsaspora owczarzaki” species are fully expanded. By far the most hits are found inside the “Deuterostomia” taxonomic group. B) Average e-values are displayed inside the same taxonomic setup. Many groups are characterized by rather dubious average e-values, such as the “Deuterostomia”-specific hits (6.08e-1 and 1.21e0 for the two queries). C) Analysis of the distribution of e-values for the two queries. Numbers of hits are shown for five e-value intervals. It is now possible to select the leftmost column (containing significant hits with e-values better than e-4), saving and re-loading the selection using the clipboard functionality, so as to recreate the above taxonomic setup with significant hits only.