Cyclin D1 and breast cancer

Cyclin D1 is one of the frequently overexpressed proteins and one of the commonly amplified genes in breast cancer. This article reviews the roles of cyclin D1 in cell-cycle regulation (normal and abnormal), mammary gland development and carcinogenesis and the relationship to oestrogen in breast tissues. It concludes by presenting the clinical, prognostic and therapeutic implications of our current knowledge of cyclin D1 in breast cancer.