Substructure filter-based methods for flagging promiscuous and/or assay interference compounds detecting promiscuous bioactives in PubChem. (A) At the 5% promiscuity cutoff, PAINS filters (red) are enriched 3.85-fold for promiscuous bioactives (p < 10−10, χ2 test) and Lilly MedChem filters (yellow) are enriched 1.85-fold for promiscuous bioactives (p < 10−10, χ2 test). (B) PAINS filters have a lower sensitivity than the Lilly MedChem filters for promiscuous bioactive compounds in PubChem. (C) However, PAINS filters have a 95% specificity for promiscuous actives, while Lilly MedChem filters have 67.5% specificity. ***: p < 0.0001.