ALB and amyotrophic lateral sclerosis: Most previous studies focused on comparing the differences between healthy controls (HCs) and ALS patients, and most found that CSF IgG levels, CSF protein levels, and the quotient of CSF albumin and blood albumin (QALB) in ALS patients were higher than those in controls (Gårde et al., 1971; Leonardi et al., 1984; Norris et al., 1993; Assialioui et al., 2022).