Our results also highlight the importance of HER-2/neu or PI3K/Akt components, including GSK-3β, β-catenin, cyclin D1, Cdk4, p21WAF1, and p27KIP1, which may serve as future targets for the development of therapeutic strategies against HER-2/neu-overexpressing breast cancer. Here, CDK4 is linked to breast carcinoma.