In addition to the SOD1 variants used as immunogens to create these anti-SOD1 nanobodies (e.g., SOD1 WT, SOD1 G93A, and SODox), we assessed reactivity to SOD1 A4V, representing the most common and aggressive variant in the North American ALS patient population [39]. Here, SOD1 is linked to amyotrophic lateral sclerosis.