Out of the cAMP-specific PDEs, the one with the highest expression in the adrenal gland is PDE8B (53), and missense variants in PDE8B have been associated with adrenocortical tumors; the mutant forms of PDE8B have compromised ability to degrade cAMP, resulting in abnormally elevated PKA activity. This evidence concerns the gene PDE8B and adrenal cortex neoplasm.