PKM and glioblastoma: To examine whether PKM2 phosphorylation is dynamically regulated in the nucleus, we performed cell fraction analyses, which showed that EGF treatment of EGFR-overexpressing U87 (U87/EGFR) (Fig. 1a) or U251 (Supplementary Fig. 1a) human glioblastoma (GBM) cells for 3 h resulted in the nuclear translocation of PKM2 with S37 phosphorylation.