MMP9 and urinary bladder carcinoma: In a series of 51 superficial bladder cancers, MMP-9 RNA expression was 2.5 fold higher in the tumours of patients with subsequent recurrence (Hara et al, 2001); we have shown that, while highly expressed in tumour tissue, MMP-9 just failed to demonstrate a significant correlation with tumour grade or to localise to a specific tumour compartment.