NUDT15 and cancer: 2014; Carter et.al. 2015). However, in contrast to MTH1, Nudt15 showed minimal enzymatic activity toward 8-oxo-dGTP and no activity toward the adenosine nucleotides 2-OH–dATP and 2-OH–ATP (Carter et.al. 2015). siRNA knockdown of Nudt15 in cancer cell lines also had no effect on their survival or increase of 8-oxo-dGTP in DNA, in contrast to siRNA depletion of MTH1 (Carter et.al. 2015).