KIF5A and amyotrophic lateral sclerosis: Notably, the presence of KIF5A-ALS aggregates also significantly reduced the levels of endogenous KIF5A, when compared with untransfected neurons (Fig. 5B), resembling what was observed in patients’ neurons as consequence of the genetic mutation, and the endogenous levels of KIF5A in neurons expressing the variant 1.2.3 were comparable with those of nontransfected cells (Fig. 5B).