Tumor biopsies from patients with newly diagnosed colon cancer will be pre-screened with an RT-qPCR test to identify tumors of the mesenchymal subtype. Patients with mesenchymal-type tumors that meet the in- and exclusion criteria will be treated with imatinib during the "window period" that normally precedes surgery. Immediately following tumor resection, biopsies will be taken from the surgical specimen. Gene and protein expression of the pre- and post-treatments biopsies will be compared to assess the effects of imatinib therapy on PDGFR- and cKIT-signalling and on the mesenchymal gene expression profile.