HMGB1 and neoplasm: However, with tumor progression, high HMGB1 expression was observed to promote tumor growth in both the 4T1 and EMT6 tumors (Fig. 2f), and lung metastasis was obvious in the 4T1-Control and EMT6-HMGB1 groups but not the 4T1-shHMGB1 and EMT6-Control groups at 4 weeks (Fig. 2g).