Erastin is an antitumor agent selective for tumor cells bearing oncogenic RAS (i.e. HRAS, KRAS). Erastin produces non-apoptotic tumor cell death by altering mitochondrial voltage-dependent anion channel (VDAC) gating allowing cations to enter mitochondria and leading to release of oxidative species causing oxidative cell death. Erastin blocks and reverses mitochondrial depolarization after microtubule destabilizers in intact cells and antagonized tubulin-induced VDAC blockage in planar bilayers. Reversal of tubulin-VDAC interaction by erastin antagonizes Warburg metabolism and restores oxidative mitochondrial metabolism.