PKM and glioblastoma: To investigate the role of PKM2 in DNA repair in tumor cells, we depleted endogenous PKM2 in U251 and U87 human glioblastoma multiforme (GBM) cells by infecting a lentivirus expressing a specific shRNA against PKM2 and rescued these cells with or without shRNA‐resistant (r) PKM2 (Figure S1A, Supporting Information), followed by the treatment of etoposide, the specific inhibitor of Topoisomerase II which can generate DNA double‐strand breaks.