GAS6 (Growth arrest-specific protein 6) is also known as AXL receptor tyrosine kinase ligand, AXLLG, is a multimodular protein that is up-regulated by a wide variety of cell types in response to growth arrest. Gas6 binds and induces signaling through the receptor tyrosine kinases Axl, Dtk, and Mer whose signaling is implicated in cell growth and survival, cell adhesion and cell migration. GAS6/AXL signaling plays a role in various processes such as endothelial cell survival during acidification by preventing apoptosis, optimal cytokine signaling during human natural killer cell development, hepatic regeneration, gonadotropin-releasing hormone neuron survival and migration, platelet activation, or regulation of thrombotic responses.