EPHA4 and amyotrophic lateral sclerosis: Following encouraging results by a study showing significant delay in disease progression in the SOD1G93A mouse model [41], the brain-penetrant, high-selectivity and high-affinity small molecule EPHa4 ligand 123C4—presumably a receptor agonist—is currently being evaluated in preclinical models for ALS by Iron Horse Therapeutics (San Diego, CA, USA) [88].