HMGB1 and lymphopenia: Third, as the cytokine-like protein, High-mobility group protein B1 (HMGB1), is released into the blood after stroke [22], [23], and HMGB1 is known to be involved in both inflammation [23], [24], [25] and immunodepression [26], we examined if HMGB1 release in the plasma correlates with T cells and lymphopenia, and studied the effects of a HMGB1 inhibitor, glycyrrhizin [27], on lymphopenia after stroke.