Because extravasation is a pivotal step of metastasis involving tumor vasopermeability factors such as VEGF [2,3] and VIAN-c4551 is a potent inhibitor of VEGF-induced vasopermeability [4,19], we aimed to investigate whether the anti-tumor action of VIAN-c4551 extended to the inhibition of the VEGF-mediated vascular permeability causing the extravasation and metastatic spread of melanoma cells. The gene discussed is VEGFA; the disease is neoplasm.