One study utilized [123I]IPT [N-(3-iodopropen-2-yl)-2β-carbomethoxy-3β-(4-chlorophenyl)tropane] to determine dopamine transporter levels in ALS patients and controls, finding significantly decreased striatal radiotracer uptake in ALS involving the caudate and putamen. Here, SLC6A3 is linked to amyotrophic lateral sclerosis.