Retrieval and processing of human CRCLM tissue. Diagram showing the dissection method for obtaining CRCLM tissue (light grey) from a liver resection specimen (dark grey). A) A slice of tissue (dark rectangle) incorporating both central and peripheral tumour, as well as a rim of surrounding liver, was obtained for fixation in formalin and subsequent embedding in paraffin wax. B) Tumour orientation and the location of the centre of the tumour were confirmed with at least four other radial incisions (dashed arrows). Six peripheral tumour samples (each approximately 0.5 cm3) were taken from within 0.75 cm of the tumour margin (marked P) taking care not to include any liver parenchyma or tumour capsule. Similar sized central tumour samples (marked C; n = 6) were then taken from an area at least 1.5 cm from the peripheral samples. Samples were immediately transferred to ice for assay or into liquid nitrogen for storage at −80°C.