There has been some controversy as to whether inflammation and neurodegeneration in MS may be two independent disease processes and, therefore, whether MS-related neurodegeneration may occur in the absence of inflammation, particularly in patients with progressive disease. A recent study analyzed the interdependence between inflammation, neurodegeneration, and disease progression in the various stages of MS, focusing especially on progressive disease. Join John DeLuca, PhD, as he discusses the results with Claudia Lucchinetti, MD, a member of the study's research team, and explores the implications of this work for the development of new therapies.