Figure 1. Members and structure of Eph/Ephrins and their bidirectional signals. (A) Members and Structure of Eph/Ephrins. (B) Both Eph receptors and ephrin are expressed in opposing cells and interact in trans to activate forward/reverse signaling. Eph receptors and ephrin are co-expressed in the same cell and interact in cis. Cis inhibition has been shown to inhibit trans signaling.