To determine whether there were any correlations among ER, Gli1 and the CSC marker ALDH1 in breast cancer specimens, we used a tissue microarray containing 100 breast cancer samples and 10 adjacent normal breast tissue or adenosis samples to analyze the expression of ER, Gli1 and ALDH1 using immunohistochemical staining. The gene discussed is ALDH1A1; the disease is breast adenosis.