Histone deacetylase 8, also known as HDAC8 and HDACL1, is a nucleus and cytoplasm protein which belongs to the histone deacetylase family and HD type 1 subfamily. Histone deacetylases (HDACs) are a growing family of enzymes implicated in transcriptional regulation by affecting the acetylation state of core histones in the nucleus of cells. HDAC8 / HDACL1 is weakly expressed in most tissues. It expressed at higher level in heart, brain, kidney and pancreas and also in liver, lung, placenta, prostate and kidney. HDAC8 / HDACL1 is responsible for the deacetylation of lysine residues on the N-terminal part of the core histones ( H2A, H2B, H3 and H4 ). Histone deacetylation gives a tag for epigenetic repression and plays an important role in transcriptional regulation, cell cycle progression and developmental events. Histone deacetylases act via the formation of large multiprotein complexes. HDAC8 / HDACL1 may play a role in smooth muscle cell contractility. HDAC8 / HDACL1 may be a potential drug target for neuroblastoma differentiation therapy using selective inhibitors, avoiding unspecific side effects.