CSF2 and Dilatation of the cerebral artery: Intriguingly, GM-CSF has been shown to promote aortic aneurysm formation (43) and the levels of GM-CSF measured in plasma and lumen of the intracranial aneurysms have also shown a direct correlation with the size of intracranial aneurysms, highlighting a common inflammatory process upregulated by M1 macrophages underlie the development of both aortic and intracranial aneurysms (44).