Adil Harroud, MD, University of California, San Francisco, San Francisco, CA, outlines the implications of the central nervous system (CNS) as a determinant of the severity of multiple sclerosis (MS). Utilizing clinical data and gene expression data from over 200 tissues and hundreds of individuals, gene enrichment was investigated to identify the contribution of specific tissues to the susceptibility and heritability of MS. While strong enrichment of genes associated with MS susceptibility was seen in immune tissues, genes implicated in MS severity were enriched in the brain and spinal cord. It was therefore concluded that the resilience of the CNS and the biological processes within neurons are critical determinants of MS severity. Based on this information, Dr Harroud is currently working to understand MS progression and identifying specific gene variants that influence disease outcomes which could be valuable therapeutic targets. This interview took place at the ACTRIMS Forum 2022 in West Palm Beach, Florida.