The stroma is important in the pathogenesis of colon cancer. Tumor-associated stromal myofibroblasts influence prognosis and predict pre-operative chemotherapy resistance. Therefore, we need to understand the responses of these myofibroblasts to current cancer management regimes. This study is designed to analyze the influence of neoadjuvant radiotherapy on myofibroblasts in cell culture models, mouse models, and in patient material.