HES1 and glioblastoma: Notably, the suppression of cell growth (Fig. 6e), colony formation (Fig. 6f, g, Supplementary Fig. 4F, G) and migratory ability (Fig. 6h, Supplementary Fig. 4H) by PLK2 overexpression can be partially rescued when combined with HES1 overexpression, indicating that PLK2 reduces the malignancy of GBM cells by inactivation of Notch signaling pathway via transcriptional regulation of HES1.