VAPB and amyotrophic lateral sclerosis: Using a lssDNA to the rat Vapb gene (vesicle-associated membrane protein-associated protein B/C), Mashimo and colleagues inserted the P56S mutation associated with amyotrophic lateral sclerosis in humans (Nishimura et al. 2004) into a floxed exon 2 of rat Vapb. Half of the rats born carried at least one floxed allele with the P56S mutation.