ACTA2 and breast cancer: To induce β-catenin stabilization specifically in BC, we crossed the same Catnb+/lox(ex3) transgenic line (Harada et al., 1999) to Acta2-CreERT2 (SMA-CreERT2) (Wendling et al., 2009);R26mTmG mice (henceforth referred to as SMACre/Tom and SMACre/β-cat for wild-type and mutant lines, respectively) (Fig.2A).