GPX3 and amyotrophic lateral sclerosis: Pairing GPX3 expression levels with ALSFRS score (a clinical questionnaire assessing functional disability and extent of neuronal loss) demonstrated that GPX3 expression was lower in those with a more progressed disease (p = 6 × 10−3, Beffect = 125 ± 39 ng/ml/ALSFRS unit, n = 48 ALS cases, adjusted for sex).