After exposure to different doses of X-rays (0, 2, 4, 6, and 8 Gy), all of the RNAs and proteins in CRC cell lines were extracted 24 h after irradiation, which showed that the expression of miR-221 was increased with the increase in the irradiation dose, whereas PTEN protein expression levels were reduced. This evidence concerns the gene PTEN and colorectal carcinoma.