PGF and acute myeloid leukemia: It can also form a heterodimer with PlGF, and this stimulates angiogenesis via the VEGFR-1/VEGFR-2 heterodimer (Autiero et al, 2003; Roy et al, 2006); this is consistent with our finding that VEGF/PlGF was present at substantially higher levels in AML patients than in the healthy controls.