Iron-driven cell death in brain immune cells may represent a previously underappreciated pathway accelerating Alzheimer's progression. This discovery could reshape therapeutic approaches by targeting metabolic vulnerabilities rather than just protein aggregates. The research reveals how amyloid-beta proteins disable a protective receptor called AXL on microglia, the brain's resident immune cells. Without functional AXL, these cells lose their ability to efficiently transport glucose through the SLC2A3 transporter, starving their mitochondria of fuel needed for ATP production. This metabolic crisis makes microglia vulnerable to ferroptosis, an iron-dependent form of cell death that releases toxic compounds damaging nearby neurons. The cascade creates a vicious cycle where dying immune cells worsen the very neurodegeneration they're meant to prevent. Using surface plasmon resonance screening, investigators identified levothyroxine—a synthetic thyroid hormone already prescribed to millions—as a compound that binds and reactivates the AXL receptor. In laboratory models, levothyroxine treatment restored normal glucose metabolism in microglia, prevented ferroptotic death, and reduced overall brain pathology. This finding represents a compelling example of drug repurposing, where existing medications find new applications based on unexpected molecular targets. The metabolic angle adds crucial nuance to Alzheimer's research, which has historically focused heavily on clearing amyloid plaques and tau tangles. While those protein aggregates remain important, this work suggests that protecting the brain's immune cells from iron-mediated death could provide complementary therapeutic benefits. However, the transition from laboratory models to human patients requires careful validation, particularly given levothyroxine's established endocrine effects and the complex interplay between thyroid function and cognitive health.