In the absence of the KLC, the KIF5A heavy chain has ahigher tendency to oligomerize in vitro (Figures 1 and 2).This result may have implications for human disease, as mutations in the divergentKIF5A tail domain cause amyotrophic lateral sclerosis (ALS) (Nicolas et al., 2018), which may conceivably alter theoligomerization properties of the motor. The gene discussed is KIF5A; the disease is amyotrophic lateral sclerosis.