SERPINB1 and Ataxia: Besides, a trend was observed for decreasing SERPINB1 plasma levels along with advancing disease stages, from mild (mean: 4.179 ng/ml), to moderate (mean: 3.886 ng/ml), to severe ataxia (mean: 2.593 ng/ml), though not statistically significant (F = 1.544; p = 0.221) (Figure S13).