A, Representative immunofluorescence images by confocal microscopy of human colorectal liver metastases (CRLM) tissue sections showing increased neutrophil infiltration and neutrophil extracellular trap (NET) formation in tumor at 20× magnification compared to non-tumor tissue of the same patient. White arrows showing neutrophils releasing NETs in merge and single staining magnified images at 40×, scale bar 50 µm. B, Protein citH3 levels were increased as evident by western blot image between the tumor (T) and non-tumor (NT) tissue of human CRLM. The blot shown is representative of three independent experiments with similar results. C, Pre-operative MPO-DNA levels detected by Elisa kit are significantly higher in patients with CRLM (n=27) compared to healthy volunteers (n=10, ***p<0.0002). D and E, Kaplan-Meier disease-free and overall survival curves were based on high versus low MPO-DNA levels post-operatively for three years (log-rank test p<0.001 for both D and E).