CRMP1 and amyotrophic lateral sclerosis: To determine the roles of total CRMP1 and CRMP1 phosphorylation at Ser522 in ALS pathogenesis, we employed Crmp1 knock-out (Crmp1−/−) mice (Cole et al., 2006) and Crmp1 knock-in (Crmp1ki/ki) mice, the latter of which we newly established by introducing the S522A mutation to block Crmp1 phosphorylation at Ser522 using the CRISPR/Cas9 system (Extended Data Fig. 2-1A).