The carbonyl content-to-GAPDH ratio values ranged from 0.7 to 2.9 (mean = 1.4 ± 0.15) in brains with Alzheimer’s disease, while those of controls had a range of 0.1 to 0.2 (mean = 0.2 ± 0.02). Here, GAPDH is linked to Alzheimer disease.