Fig. 2. Forward and reverse signals communicated downstream of the Eph-ephrin complex. Some of the known EphA—ephrin-A or EphB—ephrin-B signaling pathways are highlighted. Note that SH2 and PDZ refer to a number of identified proteins containing SH2 or PDZ domains. Grb4 is the only SH2-domain-containing protein known to bind to ephrins.