NOTCH4 and keratoconus: Because the expression and activation of Notch4 are known to be associated with endothelial components and vascular development (11, 29, 53–57), we investigated the expression levels of Notch4-ICD in the endothelial components in the pancreatic tissues of caerulein-treated KC GEMM (Fig. 5) using IF double labeling of Notch4-ICD and endomucin, an endothelial cell marker.