<p>A representative ossicle derived from unlabeled (A) and FePro labeled (B) BMSCs at 8 weeks, stained with H & E showing comparable abundant bone formation and abundant hematopoiesis. Immunohistochemistry staining for GFP of a representative ossicle derived from BMSCs labeled with both FePro and lentivirus carrying GFP (C) and control unlabeled BMSCs (D).</p