Snail1 acts as a VEGF-induced regulator of Notch1 signaling and Dll4 expression.32 In humans, genes from the NOTCH pathway (JAG1 and NOTCH2) are implicated in Alagille syndrome type 1 and 2 (OMIM 118450 and 610205), which has high similarity with the phenotype described here in patients with homozygous variants in MMP15. Interestingly, while these syndromes present with an autosomal dominant mode of inheritance, the patients reported in this study with MMP15 variants show an autosomal recessive disease. Here, DLL4 is linked to Alagille syndrome due to a JAG1 point mutation.