HMGB1 and Stroke: Additionally, HMGB1/RAGE pathway activation causes expansion of the CD11b +Gr‐1+ monocyte subpopulation, which exhibits a hyporesponsive state after stroke, as evidenced by the reduced expressions of MHC‐II and costimulatory molecules and reduced secretion of the proinflammatory cytokines TNF‐α and IL‐12.