“…All HDACi are distributed in 702 compound families (method for deriving compound families described in our earlier publication [40,41] and their structural diversity index is 0.506, which is comparable to that of the structurally diverse estrogen receptor agonist dataset. [46] Therefore, our collected HDACi are fairly diverse in structures and physicochemical properties, and they are significantly higher in numbers than the 40-200 compounds used in developing ligand-based HDACi prediction tools reported in the literatures (QSAR, [9][10][11][12][13] 3D-QSAR, [14][15][16][17][18][19] and pharmacophore [20] ). Among the 1488 HDACi and 84 weak HDACi, there are 1268 HDACi, 70 weak HDACi published before 2008, and 220 HDACi, 14 weak HDACi published since 2008.…”