This study aimed to evaluate the effects of MALAT1 modification on pathological changes, inflammation, vascular smooth muscle cell (VSMC) phenotype switching, and the underlying mechanism in intracranial aneurysms (IAs).<h4>Methods</h4>MALAT1-overexpressing (oeMALAT1), MALAT1 short hairpin (shMALAT1), and semaphorin 3C (SEMA3C)-overexpressing (oeSEMA3C) lentiviruses were transfected alone or in combination into basilar artery VSMCs originating from IA rats. The gene discussed is MALAT1; the disease is Dilatation of the cerebral artery.