Used in biomedical research to measure levels of Phosphodiesterase 4D (PDE4D) in human samples such as serum, plasma, or tissue lysates. Helps in studying inflammatory diseases, neurological disorders, and cardiovascular conditions where PDE4D activity is implicated. Commonly applied in drug development to assess target engagement and efficacy of PDE4 inhibitors. Supports quantitative analysis in cell signaling studies and biomarker validation.