HDAC9 and prostate cancer: We previously synthesized a series of 1-benzylindole derivatives with dual inhibitory activity for both HDAC and α-tubulin assembly, and MPT0B451 is one of the potent compounds inhibiting cell proliferation in various solid tumor cells, especially for human prostate cancer cells (PC-3, GI50 = 33.09 ± 0.97 nM) (Lee et al., 2017).