S100A9 and amyotrophic lateral sclerosis: Although all the proteins found in NC MCEVs were also present in ALS MCEVs, there were 12 unique proteins (CD177, CHMP4B, CSPG5, DYNC1I2, IGHV3-43, LBP, RPS29, S100A9, SAA1, SCAMP4, SCN2B and SLC16A1) found only in ALS MCEVs (Figure 3A).