HPRT1 and brain neoplasm: HPRT1 depletion (Supplementary Fig. 8e, f) inhibited TMZ treatment-induced AMPK activation in brain tumor tissues (Fig. 6c and Supplementary Fig. 8g) and enhanced TMZ-induced γ-H2AX levels (Fig. 6d and Supplementary Fig. 8h) and apoptosis (Fig. 5e and Supplementary Fig. 8i).