AXL

AXL receptor tyrosine kinase

Also known as: AXL, UFO, JTK11, Tyro7

Biology & Mechanism

AXL is a TAM family receptor tyrosine kinase (along with TYRO3 and MERTK) that mediates efferocytosis—phagocytosis of apoptotic cells and debris—in microglia. AXL uses Gas6 and Protein S as bridging ligands and signals through phosphatidylserine-exposed on apoptotic cells. AXL is a marker of disease-associated microglia and is upregulated in AD brain. AXL-mediated clearance may be protective or may also facilitate uptake of prion-like protein aggregates.

Open Questions

  • Does AXL-mediated phagocytosis of protein aggregates accelerate prion-like spread or contribute to clearance?
  • Can AXL be targeted to selectively enhance beneficial efferocytosis in neurodegeneration?
  • What is the interplay between TAM receptor signaling and TREM2 in microglial phagocytic decision-making?

Sources

Evidence Status

human tissuesingle-cell RNA-seqanimal modelin vitro assay

Disease Links

  • Alzheimer's disease
  • Parkinson's disease
  • Amyotrophic lateral sclerosis
  • Brain aging

Last reviewed: June 1, 2026