MKI67 and breast cancer: We then associated BCL6 expression with clinicopathological features and survival of breast cancer patients and found that expression of BCL6 protein was positively associated with tumor size (P = 0.004), higher tumor grade (P = 0.003), tumor lymph node metastasis (P = 0.029), advanced clinical stages (P = 0.006) and Ki67 labeling index (P = 0.002) of breast cancer (Table 2).