Our analysis also established that 132 compounds were flagged with one or more structural alerts from either a) PAINS filters , b) aggregators , c) cellular assay nuisance compounds or d) Historical Compounds. Of the 60 stereoisomers, 54 originate from the Probe Miner set. Compared to small-molecule approved drugs extracted from ChEMBL (as a set in P&D) probes are generally larger and more complex (Figure ). This correlates with higher target selectivity that, in turn, is reflected in the number of associated targets (Figure ). However, these values could be biased by approved drugs accumulating more cross-screening data and hence a wider range of secondary targets.