This challenge targets the hypothesis: **Dual-Domain Antibodies with Engineered Fc-FcRn Affinity Modulation** **Hypothesis Summary:** ## Mechanistic Overview Dual-Domain Antibodies with Engineered Fc-FcRn Affinity Modulation starts from the claim that modulating FCGRT within the disease context of neurodegeneration can redirect a disease-relevant process. The original description reads: "**Molecular Mechanism and Rationale** The neonatal Fc receptor (FcRn), encoded by the FCGRT gene, plays a crucial role in antibody pharmacokinetics through its pH-dependent binding mechanism with immunoglobulin G (IgG) antibodies. Under normal **Falsifiable Predictions:** 1. Pharmacological modulation of FCGRT 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:** $127,303 USD (composite score 0.773) **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.