Consistently, swimming also reduced the protein expression of CD31, HIF-1α, VEGFA, and VEGFR2, which suggests that the essential role of swimming is the suppression of tumor angiogenesis and that the inhibition of the HIF-1α/VEGFA/VEGFR2 axis might be an underlying mechanism by which swimming attenuates CRC tumor growth. This evidence concerns the gene PECAM1 and colorectal carcinoma.