To further validate the clinical relevance of ABCA1 as a circulating biomarker for ALS, we performed ELISA-based quantification of serum ABCA1 in an independent in-house cohort consisting of 15 patients with ALS and 15 age- and sex-matched healthy controls (Figures 7A, 7B, and S6A). This evidence concerns the gene ABCA1 and amyotrophic lateral sclerosis.