Additionally, Nakaoka et al.116used gene expression profiling to reveal that the levels of S100A9 were significantly higher in ruptured aneurysms compared to unruptured intracranial aneurysms, and early stage ruptured aneurysms showed higher levels of S100A9 than late‐stage ruptured aneurysms. This evidence concerns the gene S100A9 and Dilatation of the cerebral artery.