BMI1 and breast cancer: Experimental studies convincingly link BMI-1 to carcinogenesis, for instance, aberrant expression of BMI-1 has been associated with malignant tumors of the hematopoietic and lymphatic systems [8], [9], melanoma [10], neuroblastoma [11], endometrial carcinoma [12], non-small cell lung cancer [13] and breast cancer [14].