Angiogenesis inhibitor BT2 is a novel inhibitor of angiogenesis and vascular permeability, inhibiting ERK phosphorylation and the expression of FosB/ΔFosB, VCAM-1, and many genes involved in proliferation, migration, angiogenesis, and inflammation, interacting with MEK1, suppressing retinal CD31, pERK, VCAM-1, and VEGF-A165 expression.