CCND1 and breast cancer: On the contrary, like in our previous study [17], there was even an inverse association between the expression of the cyclins D1 and E. An early study by Kenny et al., analyzing cyclin D1 mRNA expression, came to similar conclusions, showing that cyclin D1 mRNA levels were significantly associated to relapse and breast cancer death in ER-positive disease, while no association was found in ER-negative disease [5].