Significant anti-angiogenic effects of regorafenib were observed in the investigated colon carcinoma xenografts with a significantly lower (p < 0.001) microvascular density in regorafenib-treated than in non-treated animals (8.1 ± 3.0 vs. 20.8 ± 5.7), quantified by CD31 stainings. This evidence concerns the gene PECAM1 and colon carcinoma.