Fig. 1.

Effect of β-catenin deletion on ErbB2^KI mammary tumorigenesis. (A) Kaplan–Meier analysis of tumor onset shows the consequences of β-catenin deletion during ErbB2^KI tumorigenesis. Statistical significance determined by Student’s t test. Median tumor onsets are indicated for each cohort. (B) ErbB2 expression and loss of β-catenin expression were confirmed by immunoblot analyses. (C) β-Catenin (green) was visualized by IHF staining on paraffin-embedded end-point mammary tumors, and nuclei were visualized by DAPI staining. Images were acquired by confocal microscopy. Arrow points to the stromal component of tumors. Ctnnb1^+/+ErbB2^KI, n = 6; Ctnnb1^fl/+ErbB2^K poorly differentiated, n = 5; Ctnnb1^fl/+ErbB2^KI others, n = 3; Ctnnb1^fl/flErbB2^KI, n = 5. (Scale bar: 20 μm.)