CLOCK and amyotrophic lateral sclerosis: The link could be direct with core function in these networks, as the ATX2 (ATAXIN-2) protein, which is implicated in the expression of spinocerebellar ataxia type 2 (or an increased risk of amyotrophic lateral sclerosis and Parkinsonism), is involved in the activation of the rate-limiting circadian clock component PERIOD in Drosophila (Lim and Allada, 2013) and their daily locomotor behavior (Zhang et al., 2013).