The HDAC (Histone Deacetylase) family comprises multiple members, categorized into four classes: I, II (IIa and IIb), III, and IV. Their primary function is to remove acetyl groups from histone and non-histone substrates, influencing gene expression. These enzymes localize in the cell nucleus and cytoplasm, participating in the regulation of processes such as gene silencing, the cell cycle, differentiation, and apoptosis. The expression of HDAC family members is tissue-specific and varies during different developmental stages. Mutations or dysregulation in specific HDAC genes are associated with the development of various diseases, including cancer, neurodegenerative disorders, and cardiovascular diseases, making them potential drug targets for treating these conditions.