LRP6 and coloboma: For example, eye-specific disruption of β-catenin results in eye malformations in mouse (Hägglund et al., 2013; Westenskow et al., 2009), and functional abrogation of the Wnt co-receptor LDL-receptor-related protein 6 (LRP6) or the Wnt antagonist Dickkopf 1 (DKK1) result in microphthalmia and coloboma (Lieven and Rüther, 2011; Zhou et al., 2008).