The Eph family of tyrosine kinase receptor signaling pathway is important for a variety of physiological processes during development including cell morphology, proliferation, migration and axonal guidance, dendritic spine formation and neural plasticity. Eph receptors mediate forward signaling in one cell while ephrin ligands transmit reverse signaling in an adjacent cell^1-3_.

Eph receptors consist of two large subfamilies: EphA and EphB that bind to either glycophosphatidylinositol (GPI)-anchored ephrin-A ligands or transmembrane ephrin-B ligands respectively. Ephrin ligands are divided into ephrin-A (1 to 5) and ephrin-B (1 to 3)^1,2.

Ephrin-A5 is predominantly expressed in the quiescent anterior lens epithelial cells and is highly expressed in different layers of the cortex^2,3_.

Studies show that mutations in ephrin-A5 are linked to congenital and age-related cataracts in humans and mice_. Loss of ephrin-A5 causes abnormal localization of E-cadherin and β-catenin in anterior epithelial cells and epithelial-mesenchymal-transition².