Murine intracranial aneurysms were created in female 8-12 week-old C57BL/6 mice (Charles River Laboratories, Wilmington, MA) using a method described previously.10 (link) For the antibody blockade, 100 μg/mL anti-CXCL1 antibody (MAB453, R&D Systems) or 100 μg/mL IgG2A control antibody were injected retro-orbitally every two days.