DLL1 and keratoconus: YAP activation upregulates the expression of Notch pathway inhibitors delta-like canonical Notch ligands 1 (DLL1) and 3 (DLL3) and NEDD4-like E3 ubiquitin-protein ligase (NEDD4L), while cytoplasmic YAP sequestration results in Notch-mediated subsequent KC differentiation [59,126].