NUDT1 and glioblastoma: We confirmed the requirement of MTH1 for GBM growth and survival by siRNA knock-down (26.5 ± 6.0 % viability compared to control in culture #7, p < 0.0001; and 23.7 ± 5.7 % viability compared to control in culture #18, p<0.0001), and further reassured the observed phenotype by using additional three siRNA sequences (see Supplementary Table T3 and Supplementary Figure S4).