This challenge targets the hypothesis: **N-acetylcysteine (NAC) / System Xc⁻ - Mediated GSH Support for Neurovascular Unit Protection** **Hypothesis Summary:** NAC serves as a GSH precursor and direct antioxidant to inhibit ferroptosis in cerebral microvascular endothelial cells and astrocyte end-feet, preserving tight junction integrity and AQP4 polarization to prevent BBB disruption and edema after cardiac arrest. This is the most translationally credible strategy given NAC's established safety profile, clinical familiarity in critical care, and demonstrated rescue of ferroptosis via GSH precursor pathways. Mechanism attribution to SLC7A11 requires g **Falsifiable Predictions:** 1. Pharmacological modulation of SLC7A11 (system Xc⁻) / GSH metabolism 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:** $126,000 USD (composite score 0.760) **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.