In an in vivo experimental autoimmune encephalomyelitis (EAE) model, blockade of BCAT1-mediated leucine catabolism, either through a BCAT1 inhibitor or LβhL treatment, mitigated EAE severity by decreasing HIF1α expression and IL-17 production in spinal cord mononuclear cells. Here, IL17A is linked to experimental autoimmune encephalomyelitis.