Ephrin type-A receptor 4 (EphA4)

Ephrin type-A receptor 4 (EphA4) is a member of the ephrin receptor subfamily within the receptor tyrosine kinase (RTK) family, encoded by the *EPHA4* gene[3][4]. It is a **cell surface receptor** involved in numerous developmental and physiological processes, with prominent roles in neuronal network formation, axon guidance, and cell-cell communication. In the nervous system, EphA4 regulates axonal regeneration, astroglial scarring, and spinal cord circuitry[4]. In cancer, EphA4 is a mediator of tumor cell migration, invasiveness, and angiogenesis, and its expression correlates with tumor aggressiveness and poor clinical outcome, especially in basal-like breast cancer[2]. Upon binding ephrin-A ligands, EphA4 modulates signal transduction pathways such as Rho GTPase activity, affecting cell morphology and integrin-mediated adhesion[5]. Recent studies have also implicated EphA4 in immune cell polarization during inflammation and CNS injury[6]. Preclinical research aims to modulate EphA4 activity for neuroregeneration and cancer therapy.

Other names

EPH receptor A4EPHA4EPH receptor tyrosine kinase A4Erythropoietin-producing hepatocellular carcinoma A4

Inhibition of ligand (ephrin) binding to block receptor activation and downstream signaling (e.g., with fusion proteins or monoclonal antibodies) Downregulation or inhibition of EphA4 activity to modulate axon regeneration and reduce tumor cell migration