Bmi1 is overexpressed in breast tumor tissues. A. Scatter plot shows gene expression of Bmi1 in normal (n =24) and tumorigenic (n =40) breast tissues assessed by qPCR. Log2- ratios for each dot represents data for one sample. Overexpression of Bmi1 mRNA in breast cancer, as compared to normal breast tissue, showed a median change (log2) of 2.75 folds. Statistical significance was calculated using unpaired t-test (p =0.0481). B. The images show immunohistochemical analysis for Bmi1 in normal and tumor breast tissues. Lower panel shows negative control where primary antibody was excluded.