SOD1 and amyotrophic lateral sclerosis: IL-23 production was increased by stimulation with fibrillar SOD-1 of ALS patients' PBMC's (n = 6; mean ± S.E.M; not stimulated 52 ± 11.2 pg/ml, stimulated 123 ± 24.5 pg/ml; Wilcoxon p value = 0.0156) and control subjects' PBMC's (n = 3; mean ± S.E.M; not stimulated 27.6 ± 2.9 pg/ml, stimulated 188 ± 50 pg/ml; Wilcoxon p = .1) (data not shown).