Figure 2. 5-FU chemotherapy enriches CD133⁺ cancer cells in human colon cancer patients.

Tumor tissues from human colon cancer patients without prior 5-FU therapy (n=5) and with prior 5-FU therapy (n=5) were stained with CD133-specific antibody. Brown color indicates CD133 protein expression, with counterstaining by hematoxylin in blue. Shown are representative images of colon carcinoma tissues from each of the five patients without prior 5-FU therapy (U1-5) and with 5-FU therapy (F1-5). Shown is CD133 staining intensity. Red arrows indicate CD133⁺ cells.