ALDH7A1 and neurodegenerative disease: Based on the above considerations, research focusing on the role of PDEs in the regulation of cyclic nucleotide signaling pathways in C. elegans has direct translational implications for a variety of human diseases involving dysregulation of PDEs (“PDE-opathies”), including disruptions of sensory systems, developmental and reproductive disorders, tumorigenesis, and neurodegenerative diseases (see Section 1.2).