Ephrin-B1 is signals forward or reverse signaling mechanisms. Ephrin-B1 PDZ-dependent reverse signaling controls axon guidance of the corpus callosum, whereas forward signaling is critical for normal craniofacial development.nEph receptors and ephrins are highly expressed in the brain and in the developing nervous system, where they are involved in fundamental developmental processes of the nervous system, including axon guidance, axonfasciculation, neural crest cell migration, acquisition of brain subregional identity,and neuronal cell survival. Ephrins are dramatically expressed in a wide range of regions of the vertebrate embryo including the ectoderm, mesoderm, and endoderm.nOverexpression of B-type ephrin in cancer cells is reported to correlate with high invasion and high vascularity of tumors and elevated expression of ephrin-B1 is observed in poorly differentiated invasive tumor cells and other tumors with poor clinical prognosis.