GAPDH and Huntington disease: 3‐Nitropropionic acid (3‐NP), an inhibitor of the mitochondrial citric acid cycle, produces the selective striatal degeneration and mimics the progressive locomotor deterioration of HD.52, 53 Glyceraldehyde 3‐phosphate dehydrogenase (GAPDH) is a key molecule in the glycolytic pathway.