Furthermore, a novel small molecule inhibitor, BGB324, has been tested pre-clinically in immunocompromised mice with GSC-derived MES-like GBM tumors to target the TAM (Tyro-3, Axl, and Mer) receptor tyrosine kinase family member Axl, thereby disrupting it’s signaling with ligand protein S (PROS1), has significantly improved survival and is thus under investigation in recurrent GBM models. Here, PROS1 is linked to glioblastoma.