VPA is transported in a tissue-specific manner and could serve as a wide-spectrum transporter inhibitor/substrate [10, 33], which explains the inhibition of the VPA transport system by an anion exchange inhibitor (DIDS), a diuretic drug (furosemide), and OAT substrates/inhibitors in the WT and MT ALS cell lines (Table 3). This evidence concerns the gene OAT and amyotrophic lateral sclerosis.