MKI67 and breast cancer: Cox proportional multivariate analysis showed that RXRG expression was an independent indicator of both longer breast cancer-specific survival and distant metastasis-free interval in the whole cohort (HR = 0.6; 95% CI = 0.4–0.8; p = 0.04 and HR = 0.7; 95% CI = 0.6–0.9; p = 0.025, respectively) independent of the standard prognostic parameters of breast cancer, including tumour size, histological grade, nodal stage, ER status and proliferative fraction as assessed by Ki67.