Both of these datasets challenge current assumptions in the field, which suggest that GIDs expression may be dependent on 5‐HT expression.24, 25, 26, 27 Dopamine is directly implicated in both studies: (1) the presentation of GIDs resembles some elements of classic LIDs; (2) anti‐dopaminergic drugs reduce GIDs; (3) GIDs correlate with measures of dopamine (fluorodopa in clinical trials/TH+ immunohistochemistry here), and (4) GIDs occur in association with functional improvements (Unified Parkinson Disease Rating Scale [UPDRS] in clinical studies, amphetamine rotations here). This evidence concerns the gene TH and Parkinson disease.