Figure 7. Schematic illustrating a possible role for NOTCH3 in IA. NOTCH3 is altered at the genetic polymorphisms which were predicted to alter an amino acid residue and therefore potentially the protein structure. Down-regulated expression of NOTCH3 in the cerebral artery influences angiogenesis damaging cerebrovascular endothelial repair. Up-regulated expression of NOTCH3 in neutrophil activate and promote inflammation in the cerebral artery. In a word, these abnormities in NOTCH3 cause damage to blood vessels in the brain, which can lead to the onset and development of intracranial aneurysm. Image modified from ScienceSlides (VisiScience Corp., North Carolina, USA).