. The resulting 207 pairs showed a ratio of 1:10 of ACs, with only 18 pairs having affinity differences in the range of two to three orders of magnitude. Using DUck, we evaluated ΔGQB for each HSP90α-inhibitor complex, finding that they range from 4 to 29 kcal mol -1 . With a median ΔGQB value of 21.9 kcal mol -1