PDE8B and adrenal gland neoplasm: Based on the small number of cases that have identified to date, it appears that PDE8B-mutation-associated adrenal tumors are more aggressive than those associated with mutations in PDE11A. The PDE8B adenoma-associated mutations attenuate PDE8 enzymatic activity (82), providing support for an essential role of PDE8B in adrenal function and tumorigenesis.