Figure 5

Type I lobules are enriched for basal progenitor cells. (A) Type I lobules demonstrated significantly different patterns of estrogen receptor (ER)α and progesterone receptor (PR) expression compared with other lobule types. Lobules were stained for ERα, PR, and Ki67, and the number of individual lobules in each category was quantified for each lobule type (n = 15 lobules/patient). Statistical differences were detected by chi-squared analysis. (B) Type I lobules demonstrated significantly reduced levels of EpCAM expression compared with other lobule types. Lobules were stained for EpCAM, and scored for cellular expression and intensity using Allred scoring criteria. The number of individual lobules in each category was quantified for each lobule type (n = 15 lobules/patient). Statistical differences detected by chi-squared analysis. Scale bar = 100 μm.