Some studies have found downregulation of cAMP/PKA/CREB signaling cascade in the brains of AD patients and AD animal models (Liang, Liu, Grundke‐Iqbal, Iqbal, & Gong, 2007; Puzzo et al., 2005; Xie et al., 2016). The gene discussed is CREB1; the disease is Alzheimer disease.