Tyrosine Kinase Inhibitors in Thyroid Cancer: May Axl/Gas6 Pathway be a Hidden Target?

Tyrosine kinase inhibitors are molecules that block various intracellular signaling pathways. Trials with some tyrosine kinase inhibitors showed promising results in thyroid cancer. They are thought to owe their antitumor property mainly to their effect on vascular endothelial growth factor receptor which is important in angiogenesis. Axl is a receptor tyrosine kinase shown to be involved in proliferation migration and survival of cells. Recent studies implied axl in thyroid cancer development. In this review, we aimed to discuss the mechanism of action of tyrosine kinase inhibitors in general and specifically focus on the axl/gas6 signaling pathway.