Given the sheer size of the Enamine library, there are still ample numbers of compounds that already meet the criteria mentioned above. That is, among the PNPs in the Enamine library alone, there are already 285,000 compounds with an nSPS ≥ 20, i.e. in the range that was identified as characteristic for compound classes enriched in bioactivity. It is to be expected that other vendors will also provide PNPs with these structural parameters. Our findings suggest that for future compound collection design principles of compound selection for hitfinding should include PNP-character and enrichment in bioactivity, and, thereby, extend beyond the rules of lead-or drug-likeness. Considering the currently available small molecule collections alone, if desired, a PNP screening library that promises to yield numerous hits with novel bioactivity is, in principle, readily available.