For instance, the function of soluble guanylyl cyclase seemed to be impaired in Alzheimer’s disease (AD), causing a decrease in cytosolic pools of cGMP, while, in colon cancer, the dysregulation or suppression of membrane-bound guanylyl cyclase and the overexpression of PDE10A led to a reduction in membrane-proximal pools of cGMP [2,4]. The gene discussed is PDE10A; the disease is Alzheimer disease.