The data from this paper show that elevated β-catenin levels and activity observed in Rad6B-overexpressing breast cancer subpopulations (R6B-Zshigh) require intact Wnt signaling since disruption of Wnt signaling in R6B-Zshigh cells with a signaling defective LRP6 lacking 173 amino acids in the c-tail [25] dramatically inhibits β-catenin levels and activity. This evidence concerns the gene LRP6 and breast carcinoma.