GAS6 (Growth Arrest Specific 6) is a 75-kDa vitamin K-dependent protein that functions as a ligand for TAM receptor tyrosine kinases (TYRO3, AXL, MER), playing crucial roles in immune regulation, inflammation, and cellular survival 1. The protein primarily functions through binding to its receptors to regulate diverse cellular processes including apoptosis inhibition, efferocytosis (clearance of apoptotic cells), and macrophage polarization 2. Mechanistically, GAS6 activates downstream PI3K/AKT and MAPK/ERK signaling pathways upon receptor binding, triggering actin remodeling, membrane ruffling, and macropinocytosis 3. In immune contexts, GAS6 promotes M2 macrophage polarization and enhances efferocytosis capacity, while its deficiency leads to impaired clearance of apoptotic cells and increased inflammatory responses 2. Disease relevance includes sepsis-induced cardiac dysfunction, where GAS6 provides cardioprotection through NLRP3 inflammasome inhibition 1, and cancer progression, where GAS6-AXL signaling drives drug resistance and metastasis 45. Clinically, GAS6 represents a potential therapeutic target, with intra-articular GAS6 injection showing promise in obesity-associated osteoarthritis 2 and GAS6 expression correlating with cardiac outcomes in ischemic heart disease 6.