<i>In vivo</i> immune responses were examined using a prophylactic vaccination model in GL261 glioma-bearing mice.<h4>Results</h4>NAMPT inhibition by GMX1778 depleted mitochondrial NAD<sup>+</sup>, suppressed SIRT3, and induced ROS accumulation with downregulation of GPX4, leading to ferroptosis. Here, GPX4 is linked to glioma.