Fig. 4

Pathological features of POU2F3-positive cells in the human non-neoplastic breast. POU2F3-positive cells in the non-neoplastic breast can be classified into two types. One is near myoepithelial cells with moderate to strong intensity (a, arrow). The other one is close to the lumen with generally weak intensity (a, arrowhead) but sometimes shows bright intensity, for example, when they are in ducts/acini with cystic changes (b). In some lobules, POU2F3 (c) and ER (d) are almost mutually expressed. Conversely, some POU2F3-positive cells (e) seemingly co-expressed KIT (f) (a-f: immunohistochemistry)