This normal interaction between EphB4 and ephrin-B2 therefore requires direct cell-cell contact and induces forward signaling of the receptor that leads to tumour suppression and reverse signaling through the ligand that stabilizes cell-cell adhesion and can stimulate angiogenesis if the ephrin-B2 expressing cell is an endothelial cell [3]. The gene discussed is EPHB4; the disease is neoplasm.