Fig. 1.

Large numbers of myofibroblasts exist in the stroma of human breast tumour. Paraffin sections were prepared from human non-neoplastic breast tissue (a and c) or invasive breast cancer tissue (b and d) dissected from the same individual. These sections were stained with hematoxylin and eosin (H&E) (c and d) or immunostained with an anti-α-SMA antibody (a and b). α-SMA-positive myoepithelial cells surrounding epithelial cells (an arrow in a) are observed in normal tissue (a), whilst α-SMA-positive myofibroblasts (arrows in b) are only found in the tumour-associated stroma (b) (from Ref. [22]).