pede4dThe PDE4 family contains four genes (PDE4A to PDE4D), only PDE4A, PDE4B, and PDE4D are expressed in the heart, each of which regulates different cAMP-dependentPharmacological phosphodiesterase 4D (PDE4D) inhibition shows therapeutic potential to restore memory function in Alzheimer's disease (AD), but will likely evoke adverse side effects. As