HMGB1 and diabetes mellitus: Our previous studies demonstrated that HMGB1 can be either passively released from damaged pancreatic beta cells or actively secreted by islet-infiltrating immunocytes such as dendritic cells (DCs) and macrophages [14, 15], and that blockade of HMGB1 in 8- or 12-week-old NOD mice delayed diabetes onset [15].