APOE and amyotrophic lateral sclerosis: Also, the intracellular transport cluster (Alami et al., 2014; Foran et al., 2014) contains the highly down-regulated gene, APOE, whose product is involved in mitochondrial oxidative stress in ALS, and its variants have been correlated to an increased risk of bulbar-onset of human ALS (Praline et al., 2011).