The sets are compared by exact matches in Table . The resulting matrix is unique in that no individual source has published a comparable analysis. However, some results were unexpected. The first surprise was the low intersection between MLP and the calculated sets. We attribute this to the 80 compounds from the MLP set without bioactivity data on P&D. In addition, 203 have a primary target potency are above the 100 nM threshold. The unexpectedly high overlap between the Chemical Probes Portal and Tool Compound Sets is a consequence of the (already mentioned) inclusion of the former in the latter but without data-supported evaluation. Also surprising is the low overlap between the two calculated sets, even though the data sources and selection criteria were conceptually similar. However, the main goal of the Tool Compound Set was to select effective agonists or antagonists with a high stringency for target selection and cell potency. Table A matrix showing the intersections between 12 sources. This was computed using the InChIKey exact match for the standardised structures from the P&D portal. The diagonal figures in white represent the source counts in Table .