RRM2B and colonic neoplasm: P53R2, also known as RRM2B, is primarily identified as a ribonucleotide reductase small subunit in the colon cancer cell line by Japanese researchers [8], and is a downstream target gene of the p53 gene consisting of 9 exons and 1 intron that binds to the p53 sequence, could provides dNTPs for DNA synthesis and repair in the G1 and G2 phases of the cell cycle [9, 10].