GDNF and brain disorder: HDACis may be used to treat various brain diseases based on three possible mechanisms: (a) by reducing the anti‐inflammatory effects involving inflammatory factors, such as TNF‐alpha or IL‐1beta,38 (b) by reducing the neurotoxicity of β‐amyloid‐beta and other neurotoxic molecules,39 or (c) by increasing neuroprotective proteins such as glial cell‐derived neurotrophic factor or BDNF.40