Gas6 (growth arrest-specific gene 6) is the last addition to the family of 
plasma vitamin K-dependent proteins. Gas6 was cloned and characterized in 1993 
and found to be similar to the plasma anticoagulant protein S. Soon after it was 
recognized as a growth factor-like molecule, as it interacted with receptor 
tyrosine kinases (RTKs) of the TAM family; Tyro3, Axl, and MerTK. Since then, 
the role of Gas6, protein S, and the TAM receptors has been found to be 
important in inflammation, hemostasis, and cancer, making this system an 
interesting target in biomedicine. Gas6 employs a unique mechanism of action, 
interacting through its vitamin K-dependent Gla module with 
phosphatidylserine-containing membranes and through its carboxy-terminal LG 
domains with the TAM membrane receptors. The fact that these proteins are 
affected by anti-vitamin K therapy is discussed in detail.