The Northern Ireland Cancer Registry was used to identify 1426 stage II and III colon cancer patients undergoing surgical resection between 2004 and 2008 (Figure 1). Rectal cancers were excluded as neoadjuvant radiotherapy could potentially alter tumour expression profiles. Ethical approval through the Northern Ireland Biobank (NIB reference number 13–0087) permitted retrieval of formalin-fixed, paraffin-embedded (FFPE) tissue blocks for patients within two of the five regional Health and Social Care trusts. For this molecular pathological epidemiology study, the final cohort was subsequently restricted to only include patients within the biobank remit (n=740, 51.9%). These patients were representative of the overall Northern Ireland cohort with respect to age, sex, stage, and adjuvant chemotherapy receipt (Supplementary Table 1).