Following repeat testing in triplicate of the original solution, 7.4K compounds were confirmed. To reduce numbers for concentration -response assays, cheminformatics filters were applied: removing pan-assay interference compounds (PAINS) and other structural alert flags, frequent hitters, compounds active in the ADP-Glo TM counter-assay and application of a 65% minimum inhibition cutoff reduced numbers to 1.1K. A total of 834 (76%) compounds demonstrated activity in a concentration response curve (CRC) format. Selecting across compound clusters generated from Morgan fingerprints into a self-organized map to ensure adequate representation of chemical classes, 221 compounds were either repurchased from commercial vendors or retrieved from the parent compound collection and rescreened from powder stocks. 124 (56%) were confirmed following testing of new powder stock, of which only 23 (19%) maintained activity following an additional HPLC purification (Figure ).