Figure 5. Most Rb^Δfl mammary tumors express variable levels of basal cytokeratins, but not ERα.

Representative IHC of tumors 2, 4, 9, and 11 for CK5 (A–D), CK14 (E–H), ERα (I–L), and β-catenin (M–P). Inset in D shows CK5 expression in squamous area. Arrows in M mark cells surrounding keratinized area (Ker) with nuclear localized β-catenin. Original magnification, ×400 (A–P and D, inset).