Differential EDN3 protein expression in human breast cancer and its clinical relevance. (a) Abundant EDN3 protein expression in normal breast epithelium. (b) Magnification of specimen shown in (a). (c) Representative invasive-ductal carcinoma showing moderate EDN3 protein expression. (d) Magnification of specimen shown in (c). (e) Representative invasive-ductal carcinoma with substantial loss of EDN3 protein expression. (f) Magnification of specimen shown in (e). Kaplan-Meier curves indicating that retaining high EDN3 protein expression (immunoreactivity score of at least 8) in the tumour is significantly associated with more favourable (g) breast cancer-specific survival (P = 0.022, log-rank test) but not (h) disease-free survival. Magnifications: ×100 (a, c, e), ×200 (b, d, f). EDN3, endothelin-3.