MBP and relapsing-remitting multiple sclerosis: In a clinical trial published in 2000, RRMS patients were treated with an altered peptide ligand (APL) of myelin basic protein (MBP) with the intention of tolerizing pathogenic MBP-reactive T cells or deflecting their differentiation towards an immunosuppressive, regulatory, or innocuous T-helper 2 (Th2) phenotype [29].