In a study of 253 primary breast cancer cases, elevated cyclin D1 mRNA levels in ER+ tumors were significantly associated with increased risk of recurrence (P = 0.0016), local relapse (P = 0.025), distant metastasis (P = 0.019), and mortality (P = 0.025), whereas no such association was observed in ER-negative tumors 3. This evidence concerns the gene CCND1 and breast carcinoma.