NUDT1 and gastric cancer: Moreover, after depleting MTH1 by siRNA or treated by compound MI-743, both MGC-803 and HGC-27 cells became more sensitive to H2O2 treatment (Fig. 7i), indicating that the expression of MTH1 or its activity plays a key role in these two gastric cancer cells’ survival, and the cellular effects of MI-743 are indeed dependent on MTH1 in these two cancer cell lines.