SERPINE1 and breast cancer: High intratumoral levels of uPA, PAI‐1, and, especially, their heteromeric complexes have been identified as independent predictive factors for impaired survival (Andreasen etal, 1997; Schmitt etal, 1997; Knoop etal, 1998; Duffy etal, 1999; Foekens etal, 2000; Janicke etal, 2001; Sten‐Linder etal, 2001; Look etal, 2002; Manders etal, 2004b) and treatment response (Harbeck etal, 2002a; Harbeck etal, 2002b; Manders etal, 2004a; Manders etal, 2004c) in early breast cancer, irrespective of the underlying histopathological subtype.