Figure 2. Schematic model summarizing a possible scenario of the tumor promoting mechanism involving simultaneous EphA/ephrin-A and EphB/ephrin-B signaling. E-cadherin-mediated cell adhesion (green) allows the interaction between EphAs and ephrin-As (yellow), thereby blocking the MAPK induced cell proliferation. EphB (purple)/ephrin-B (blue) interactions can lead to the activation of the ADAM10 protease (yellow ovoid) which cleaves not only the Eph complex but also the extracellular part of E-cadherin. As a consequence cell adhesion is disrupted and impedes the interaction of EphAs with their ligands and thus relieves the block of MAPK activation promoting tumor formation/growth.