ZEB1 and posterior polymorphous corneal dystrophy: Importantly, key findings from the transcriptomic profiling of human PPCD endothelium [20] were recapitulated in the ZEB1 knockout cell line, further supporting the utility of the CRISPR-Cas9-mediated knockout of ZEB1 in CEnC to gain a better understanding of the molecular factors central to the pathogenesis of PPCD.