MAP2K1 and cataract: Transgenic mice that express a constitutively active mutant of Mitogen-activated protein kinase kinase 1 (MEK1) [MEK1(E)] under the control of the αA-crystallin promoter develop macrophthalmia and severe cataracts with major histological abnormalities of the lens that are followed by lens rupture (Gong et al., 2001).