PDE4DIP (phosphodiesterase 4D interacting protein) is a Golgi/centrosome-associated scaffolding protein that regulates microtubule dynamics and intracellular signaling compartmentalization. As a component of the AKAP9 complex, PDE4DIP recruits CAMSAP2 to the Golgi apparatus to tether non-centrosomal microtubules, facilitating polarized cell movement 12. At the centrosome, PDE4DIP cooperates with AKAP9, EB1/MAPRE1, and CDK5RAP2 to nucleate and extend microtubules, supporting directed cell migration and mitotic spindle orientation 3. In cardiac tissue, PDE4DIP anchors phosphodiesterase enzymes to regulate cAMP signaling microdomains, controlling heart rate, conduction velocity, and excitation-contraction coupling 4. Inherited PDE4DIP mutations impair PKA compartmentalization and cause early-onset atrial fibrillation with conduction disease, particularly through epistatic interaction with desmin mutations 5. PDE4DIP dysfunction also contributes to left ventricular non-compaction cardiomyopathy via dysregulation of the Rho-ROCK pathway 6. PDE4DIP is oncogenic in lung and colorectal cancers. In non-small cell lung cancer, PDE4DIP overexpression promotes cell proliferation by stabilizing PKA RIIα at the Golgi, suppressing apoptosis 7. In colorectal cancer, PDE4DIP enhances RAS/ERK signaling by suppressing the RasGAP neurofibromin through PKCε-mediated degradation, conferring MEK inhibitor resistance 8. Genomic variants in PDE4DIP associate with atrial fibrillation, stroke, and heart failure 49.