HMGB1 is a member of a subfamily of the HMG proteins. On average, HMGB1 is found at concentrations of 10 6 molecules per cell and non-specifically binds to the minor grooves in DNA (19) . This binding is regulated by two 80 amino acid HMG-1 domains (or boxes), each structurally represented as three α-helices in a characteristic L-shaped fold (20) . The nuclear localization of HMGB1 and its affinity for DNA is regulated through phosphorylation and acetylation, and has been found to have a dynamic relationship with chromatin (21) . Like the other members of this protein family, HMGB1 plays an important role in DNA architecture and transcriptional regulation.