CDK4 and breast carcinoma: Additionally, HSP suppressed aromatase enzyme activity, cyclin D1, CDK4, Bcl-xL, pS2 and induces CCAAT/C/EBP, pERK-1&-2, p57Kip2 expression, which contributes to reducing the tumour growth in MCF-7 breast cancer cells and female athymic mice model both in vivo and in vitro [59, 60].