Representative immunohistochemical images demonstrating negative, weak, moderate and high HMGB2 expression in breast cancer tissues are shown in Fig. 1. HMGB2 was expressed much more highly in breast cancer (111/185, 60.00%) than in noncancerous breast tissues (36/185, 19.46%) (P < 0.01). The gene discussed is HMGB2; the disease is breast cancer.