Using the subcutaneous colon cancer model in mice, we carried out three exponential increasing concentration levels of Fcε-PE40 chimeric toxin which were 10 μg, 100 μg and 1 mg while 100 μg and 1 mg Fcε-PE40 chimeric toxin could effectively inhibit colon cancer development in vivo. This evidence concerns the gene FECH and colonic neoplasm.