In intracranial aneurysms, multiple factors and biochemical pathways are believed to be involved in the event of a rupture. The epidermal growth factor receptor (EGFR) activation pathway is of particular interest as a way to understand and target the mechanism of rupture due to its established role in cellular proliferation and inflammation. Furthermore, unfolded protein responses in vascular cells’ endoplasmic reticulum (ER), known as ER stress, have emerged as a potential downstream mechanism by which inflammatory EGFR activation may lead to aneurysm rupture. The purpose of this project was to investigate the role of EGFR inhibition on the aneurysm rupture rate in a preclinical model, investigate the role of ER stress induction on the aneurysm rupture rate, and confirm which cellular phenomenon lies upstream in this mechanistic cascade. Based on analyses of aneurysm rupture rate and gene expression in the Circle of Willis, ER stress and inflammatory unfolded protein responses were found to be downstream of initial EGFR activation, which may be an effective therapeutic target for preventing aneurysm rupture in a clinical setting.