PLEKHG5 and amyotrophic lateral sclerosis: In order to establish a potential link between the reduced secretion of mutant SOD1 and PLEKHG5, we analyzed the expression levels of PLEKHG5 in both ALS lines by Western blot (Fig. 7I) and detected a significantly lower expression of both PLEKHG5 isoforms in the SOD1-ALS lines (Fig. 7J).