Fig. 2

REG and REG + aPD1 significantly inhibit tumor growth and liver metastasis in orthotopic CT26 colon tumors. a Study design. Gray arrowhead indicates imaging/sampling before first drug administration for baseline determination. b Tumor growth inhibition. Mean RTV given as a percentage of the baseline volumes ± SD (n = 6–7). c Representative images. First panel: dissected tumors; second panel: T2-weighted MR images (white arrows demarcate tumors); third panel: TUNEL staining (red) with DAPI stained nuclei (blue); fourth panel: livers with metastases depicted by white arrows. Scale bar: 10 mm (MRI and ex vivo) and 100 µm (TUNEL). d Quantification of TUNEL stainings (tumor apoptosis) from frozen tumor sections at study end with mean values ± SD (n = 5–7) and individual values (dots). Statistical significance (^#day 11; *day 14): *^/#p < 0.05; **^/##p < 0.01; ***^/###p < 0.001. e Number of mice with liver metastases compared with total number of mice and percentages (number in %)