No / Improved understanding of the involvement of matrix metalloproteinases (MMPs), including membrane-type MMPs (MT-MMPs), in human tumours has potential diagnostic, prognostic and therapeutic implications. We assessed the relationship between MT-MMP expression and clinicopathological parameters in human non-small cell lung cancer (NSCLC) and histologically normal lung tissue by quantitative Real Time PCR (qRT-PCR). All MT-MMPs (MMPs 14-17, 24 and 25) were detected by qRT-PCR with significantly higher MMP-14, -15 and -17 expression observed in tumour relative to normal lung specimens. MMP-16 was undetectable in normal lung but expressed in 8% tumours. MMP-15 demonstrated significant overexpression in adenocarcinomas relative to squamous cell carcinomas and normal lung tissue. MMP-14 mRNA expression strongly correlated to MMP-14 proteolytic activity in preclinical tumour models, indicating that qRT-PCR may predict MMP-14 activity levels in NSCLC. These data suggest that MMP-14, -15 and -17 may be good markers of disease, or therapeutic targets for treatment of human NSCLC.