PDE11A encodes phosphodiesterase 11A, a dual-substrate enzyme that regulates intracellular signaling by hydrolyzing both cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP) to their respective 5'-monophosphates 1. The enzyme exhibits Km values of 0.52 μM for cGMP and 1.04 μM for cAMP with similar Vmax values, making it capable of regulating both cyclic nucleotides under physiological conditions 1. PDE11A contains an N-terminal GAF domain homologous to other signaling molecules, which may serve as an allosteric binding site for cGMP or other small ligands 1. The gene produces at least four splice variants (PDE11A1-4) with distinct tissue expression profiles and unique N-terminal regulatory regions 2. Expression is highest in skeletal muscle, prostate, kidney, liver, pituitary, salivary glands, and testis 1, with protein localization in epithelial, endothelial, and smooth muscle cells across various tissues 3. Clinically, PDE11A mutations are associated with primary pigmented nodular adrenocortical disease and Cushing syndrome 4. Polymorphisms in PDE11A have been linked to testicular cancer susceptibility and altered sperm parameters 5, while increased expression correlates with glioblastoma proliferation and poor prognosis 4.