This challenge targets the hypothesis: **GBA1 Loss Triggers a TFEB-to-TFE3 Compensatory Switch in A9 Dopaminergic Neurons that is Defective Due to LAMP2A Insufficiency** **Hypothesis Summary:** A9 dopaminergic neurons uniquely co-express TFEB and TFE3 at high levels, with TFE3 serving as a compensatory backup transcription factor for TFEB under lysosomal stress. In GBA1 deficiency, TFEB activation initially upregulates the CLEAR network to restore lysosomal biogenesis. However, in these neurons, this compensatory response fails because the newly synthesized LAMP2A protein cannot properly integrate into lysosomal membranes due to a concurrent defect in VPS35-mediated trafficking. The ac **Falsifiable Predictions:** 1. Pharmacological modulation of TFEB 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.