Figure 1.

Rare K10^pos cells are most frequently present in breast glands of women >30 years of age. (A) Immunoperoxidase staining demonstrating expression of K10 in a small subset of luminal cells. Scale bar, 50 µm. (B) Proportion of biopsies with K10^pos cells in breast gland structures from women divided into two age groups. Note that the number of K10^pos biopsies are significantly higher in women aged >30 years (10 of 23) compared with those aged <30 years (3 of 23) (Pearson’s Chi-square test, p<0.05). Abbreviation: K10^pos, K10-positive.