PDGFRB and Dilatation of the cerebral artery: In this study, we utilized single-cell sequencing and immunofluorescence to uncover phenotype modulation of smooth muscle cells (SMCs) in fusiform intracranial aneurysms (FIAs), subsequently elucidating the underlying genetic factors contributing to these processes by confirming the presence of the PDGFRβ activating variant in our patient cohort.