PDE7B is a cAMP-specific phosphodiesterase that hydrolyzes the second messenger cAMP, a key regulator of physiological processes 1. The enzyme shows highest expression in brain, heart, and liver tissues, with kinetic specificity for cAMP (Km 0.1-0.2 μM) and sensitivity to dipyridamole inhibition 1. PDE7B may regulate cAMP-mediated neural activity and metabolism in the brain 2. Dysregulation of PDE7B has significant disease relevance. In hepatocellular carcinoma (HCC), PDE7B functions as a tumor suppressor whose downregulation promotes progression 3. Promoter hypermethylation silences PDE7B expression in HCC tissues, correlating with poor recurrence and prognosis 4. PDE7B overexpression inhibits HCC proliferation, metastasis, and epithelial-mesenchymal transition through the PI3K/AKT pathway 4. Conversely, high PDE7B expression predicts poor outcomes in cytogenetically normal acute myeloid leukemia 5. Clinically, PDE7B participates in diverse pathological processes: circular PDE7B RNA promotes keloid fibroblast proliferation via miR-331-3p/CDK6 regulation 6, while downregulation of linear PDE7B in trophoblasts contributes to preeclampsia by disrupting the PDE7B-cAMP signaling pathway 7. These findings suggest PDE7B as a potential therapeutic target in cancer and other diseases.