Low levels of dNTPs have been linked to DNA replication stress in early precancerous lesions (Bester et al., 2011), while aberrantly high RRM2 expression correlates with poor cancer prognosis (Ferrandina et al., 2010; Morikawa et al., 2010a,b; Satow et al., 2010; Jones et al., 2011; Kretschmer et al., 2011). Here, RRM2 is linked to cancer.