In the serum of AD patients, significantly elevated levels of clusterin (correlated with disease severity) [24], significantly decreased levels of beta carotene [34], catalase [26], gamma tocopherol [39], glutathione peroxidase [26], Mg [30], NO [22], retinol [34], and levels of Cu similar to those of healthy controls [30] were found. This evidence concerns the gene CLU and Alzheimer disease.