Used in clinical diagnostics to quantitatively measure carcinoembryonic antigen levels in human serum or plasma. Helps in monitoring cancer progression, particularly colorectal cancer, and assessing response to treatment. Also used in research settings to study tumor markers and immune system interactions. The assay supports early detection of recurrence after surgery and aids in evaluating therapeutic efficacy. Widely applied in hospitals, diagnostic labs, and oncology research due to its sensitivity and specificity.