Tubastatin A is a potent HDAC6 inhibitor with an IC50 value of 15 nM. Comparatively, it demonstrates over 1,000-fold selectivity against all other HDAC isoforms (IC50s >16 μM), excluding HDAC8 (IC50 = 0.9 μM). Tubastatin A induces α-tubulin hyperacetylation at 2.5 μM in primary cortical neuron cultures. In a model of oxidative stress induced by glutathione depletion, tubastatin A displays dose-dependent neuronal protection of primary cortical neuron cultures at 5-10 μM.