Colorectal cancer (CRC) is one of the most common malignancies and causes of cancer deaths in the western world.12 We have previously shown that serum MMP-8 levels increase in CRC and correlate with distant metastasis and weaker tumour inflammatory cell infiltrate, as assessed from the haematoxylin and eosin (H&E) slides.13 This led us to hypothesise that high-serum MMP-8 levels could be associated with adverse patient outcome. This evidence concerns the gene MMP8 and cancer.