KT-531exhibited a superior in vitro profile when comparedto the current literature HDAC6 inhibitor, Nexturastat, which hadcomparable HDAC6 potency (IC50 = 12.4 nM) but a lower selectivitymargin (19-fold; next nearest target HDAC3 with IC50 =238 nM) (Table S2b).51,52 KT-531 also demonstrated higher cytotoxicity than Nexturastat inMV4-11 cancer cells (IC50-Nexturastat = 1.68 μM,IC50-KT-531 = 0.42 μM) (Table S2b, Figure 1b). This evidence concerns the gene HDAC6 and cancer.