In mouse embryos, similar phenotypes of arteriovenous malformations (AVM) were reported in case of mutations in the Notch ligand DLL4, the Notch signaling transcription factor CSL, as well as the Notch targets HEY1/2, with additionally upregulated venous marker expression in case of mutated DLL4 5, 12, 13. Here, DLL4 is linked to arteriovenous hemangioma/malformation.