Our current results provide evidence that the presence of the A. heterophyllus extract could mitigate the in vivo gene expression of Cyp2c37 and reduce the in vitro activities of human recombinant CYP2C9 and 2C19 isoforms, thereby providing strong evidence for its inhibitory and antagonistic effect on CYP2C9’s role in CRC. This evidence concerns the gene CYP2C9 and colorectal carcinoma.