TCF4 and Fuchs endothelial corneal dystrophy: Mis-splicing was also observed in the cornea, suggesting that zebrafish mbnl mutants may also model the genetic disorder Fuchs endothelial corneal dystrophy, a subtype of which was recently shown to be caused by an expanded CUG repeat that is expressed from an intron of the TCF4 gene and is associated with MBNL protein sequestration and mis-splicing (Fig. 3E; Fig. S6E) (Mootha et al., 2017, 2015; Wieben et al., 2017; Winkler et al., 2018).