An increased HDAC6 protein level is observed in the cortices and hippocampi of AD postmortem brain samples (Ding et al., 2008), and reducing endogenous HDAC6 restores the learning and memory deficits and α-tubulin acetylation in an AD mouse model (Govindarajan et al., 2013). Here, HDAC6 is linked to Alzheimer disease.