SOD2 and glioblastoma: Knockdown of SOD2 sensitized TMZ-resistant GBM cells to erastin-mediated ferroptosis, as indicated by a depression in the drug–response curve (Figure 5E), marked suppression of the colony-forming ability (Figure 5F), and upregulation of the ferroptosis marker Prostaglandin Synthase-2 (PTGS2) (Figure 5G).