Hazard ratios derived from the Cox regression analysis and related to PFS and OS were 0.37 (P=0.045) and 0.21 (P=0.013), respectively, for those with low-grade tumours, 0.25 (P=0.015) and 0.23 (P=0.016), respectively, for ER negative tumours, and 0.24 (P=0.012) and 0.25 (P=0.016), respectively, for PR-negative tumours. The gene discussed is PGR; the disease is neoplasm.