To test this hypothesis, we generated Epha2-knockout mice on mixed FVB:C57BL/6J (50:50) genetic background and determined cataract development in Epha2+/+ (n = 17), Epha2+/− (n = 22), and Epha2−/− (n = 23) mice from 11 to 64 weeks of age or until severe cataract developed. The gene discussed is EPHA2; the disease is cataract.