Ribonucleotide reductase subunit M2 (RRM2) encodes the catalytic subunit of ribonucleotide reductase (RNR), which is a hetero-tetramer consisting of two RRM1 and two RRM2 subunits and is involved in regulating DNA synthesis and modifying proteins (5), and is a rate-limiting molecule during the conversion of ribonucleoside triphosphates into dNTPs in the G2 phase of cell cycle (6) and shows elevated levels in some cancers (7, 8). Here, RRM2 is linked to cancer.