GAS6 and acute myeloid leukemia: In parallel with considerations of targeting TAM in AML, TAM kinases are especially important in prosurvival signaling under conditions of stress and can potentially promote cancer cell survival during leukemia therapy (Fig. 3).159 GAS6, an upstream activation factor of the TAM family, binds to AXL and MERTK with high affinity and is a common ligand for all three TAM RTKs (Fig. 3).