LC-MS/MS Proteomics was performed to determine proteomic differences between colon adenocarcinoma (CA) tissues and patient-matched normal colon tissues, CA-derived primary cell lines and NC-derived primary cells, and between LGCA tissues and cell lines and HGCA tissues and cell lines. Biological processes which may link the renin-angiotensin system and CA were investigated, revealing enrichment of various signalling pathways that may play roles in CA onset and progression directly or via the renin-angiotensin system.