The present invention for the first time demonstrated that: (1) bone marrow-derived pluripotent tissue stem cells can be induced in peripheral blood by intravenously administering tissue extract prepared from isolated skin pieces; (2) the substance in the isolated skin pieces, which is responsible for mobilizing bone marrow-derived pluripotent tissue stem cells to peripheral blood, is HMGB1; and (3) HMGB1 with the activity of mobilizing bone marrow-derived pluripotent stem cells to peripheral blood can be easily purified from cultured cells.