This challenge targets the hypothesis: **Iron-driven lipid peroxidation and GPX4 failure create a ferroptotic amplification loop** **Hypothesis Summary:** Labile Fe2+ converts H2O2 into hydroxyl radicals, driving phospholipid peroxidation that consumes GSH and disables GPX4-dependent detoxification. Membrane damage, mitochondrial failure, and further ROS production then increase the substrate load for Fenton chemistry, reinforcing ferroptotic commitment. This loop is especially plausible in substantia nigra neurons with high iron and oxidative burden. **Falsifiable Predictions:** 1. Pharmacological modulation of GPX4; SLC7A11; ACSL4; TFRC; FTH1; FTL will alter neurodegeneration markers in validated models by ≥20% 2. Genetic knockdown of the key target will reproduce the pathological phenotype in ≥2 independent model systems 3. Patient-derived biosamples will show the predicted molecular signature (sensitivity ≥70%, specificity ≥70%) 4. Mechanistic intervention at the proposed node will rescue neuronal viability in vitro by ≥30% **Bounty Tier:** $125,000 USD (composite score 0.750) **Challenge Type:** Open — any team may submit experimental evidence supporting or refuting this hypothesis **Success Criteria:** Peer-reviewed evidence demonstrating mechanistic validation of ≥2 of the 4 predictions, with independent replication.