CD9 and amyotrophic lateral sclerosis: Direct comparisons of Treg EV characterization from the ALS patient-derived Treg EVs and the control-derived Treg EVs show the same common exosome markers of CD9, CD63, and CD81 (Supplementary Figure 1C) while also having the conserved Treg-associated markers of CD2, CD4, CD25, CD44, CD29, and HLA-DRDPDQ (Supplementary Figure 1D) as determined by MACSPlex exosome analysis.