Deletion of the Apc proteins from murine mammary epithelium. (A) Mammary gland sections from Apc2+/+ and Apc2-/- mice were labeled for Apc2 using fluorescent IHC. Whilst Apc2 is expressed in Wt epithelium, Apc2-/- glands displayed comprehensive Apc2 loss (scale bar, 50µm). (B) Virgin mammary gland sections from 10 week old Blg-Cre+Rosa26+ mice were labeled for β-galactosidase to assess Cre mediated recombination. Recombination occurred in a heterogeneous manner, primarily within luminal cells (white arrowheads) but occasionally detectable in apparent non-luminal cells (grey arrowhead) (scale bar, 25µm). (C) Labeling of Virgin mammary glands section from 10 week old Blg-Cre+Apcfl/fl mice for Apc using fluorescent IHC revealed a heterogeneous pattern of loss in epithelial cells (scale bar, 50µm in main image, 25µm in inlay).