Moreover, it is confusing whether the protective role of NMNAT in the AD animal models comes from its chaperone-like activity or enzymatic activity, given that NAD+ is an essential cofactor in cellular processes such as transcriptional regulation (D'Amours et al., 1998; Shogren-Knaak et al., 2006; Zhang et al., 2009) and oxidative reactions (Lewis et al., 2014). This evidence concerns the gene NMNAT1 and Alzheimer disease.