Interventional and stroke specialists sometimes find it easy to focus on the case load that presents to us and concentrate on the challenges of curing individual disabilities and preventing individual disasters. However, if one takes a step back from the clinic and looks at our field of specialty from a larger perspective, one is impressed by the scope and rate of change that has occurred in the past several years. One topic that has seen especially dramatic progress is our understanding of intracranial atherosclerotic disease.