However, some authors have reported that deletion of cyclin D1 can play a protector role, thus protecting against the development of breast carcinoma.10,40 In fact, cyclin D1 overexpression can be a predictor of poor prognosis.37,41,42 Ahlin et al found that cyclin D1 overexpression was associated with a high proliferative index and an increased risk of mortality in patients with ER positive breast cancer but not in those with ER negative breast cancer.43 Here, CCND1 is linked to breast carcinoma.