TEK and acute myeloid leukemia: Overall, the role of the Ang1/Ang2/Tie2 axis in AML appears somewhat complex, likely involving reversal of the balance of Ang1 versus Ang2 (which have distinct and possibly opposing agonist/antagonist functions) as they compete for binding with Tie2, and is probably further influenced by prevailing VEGF-A levels (Loges et al., 2005).