Deacetylases are enzymes that remove acetyl groups from proteins, a process known as deacetylation. This modification can influence protein function, stability, and interactions, playing a crucial role in various cellular processes, including gene expression and metabolism. There are several types of deacetylases, with the most well-known being histone deacetylases (HDACs) and sirtuins. HDACs primarily regulate gene expression by modifying histones, while sirtuins are involved in cellular stress responses and aging. Both types of deacetylases are important for maintaining cellular homeostasis and have implications in diseases such as cancer and neurodegeneration.