Data-driven cutpoint analysis using X-tile software [36] identified a sub-population of patients with the highest levels of nuclear cyclin D1 within the stromal cell compartment (Supplementary Figure 1A) to be at a significantly increased risk of breast cancer recurrence (Cox Regression Hazard Ratio = 1.76 (CI: 1.20-2.57), p = 0.004) (Figure 1C). This evidence concerns the gene CCND1 and breast carcinoma.