KRT4 and posterior polymorphous corneal dystrophy: To determine if the ZEB1+/- CEnC line sufficiently recapitulates the epithelial-like gene expression observed in PPCD3, we compared the expression of a random selection of corneal epithelial- (CDH1, CLDN1, DSG2, EPCAM, F11R, KRT4, LGALS3, SFN, GRHL2 and OVOL2) and endothelial- (ADCYAP1R1, CDH2, MEGF10, NUAK1, ZEB1) associated genes that are differentially expressed in PPCD across the four CEnC lines (Fig 1E).