SERPINE1 and cancer: Thus, the level of PAI-1 in primary tumours is one of the most informative biochemical prognostic markers in several cancer types (Duffy, 1996; Harbeck et al, 1998; Knoop et al, 1998; Duffy et al, 1999; Look and Foekens, 1999; Janicke et al, 2001; Look et al, 2002).