Our qRT-PCR (Figure 6A) and western blot (Figures 6B,C) analyses showed that HDAC1, HDAC2, and HDAC3 mRNA and protein expression levels in the cerebral cortex of AD model mice were significantly increased (p < 0.01) compared with levels observed in WT mice with or without SFN treatment, and obviously decreased (p < 0.05; p < 0.01) in AD model mice treated with SFN relative to the levels observed in AD model mice. Here, HDAC2 is linked to Alzheimer disease.