This product is used for in vitro quantitative detection of the contents of carcinoembryonic antigen (CEA), neuron-specific enolase (NSE), and cytokeratin 19 fragment (CYFRA21-1) in human serum. It is mainly used for dynamic monitoring of patients with malignant tumors to assist in judging disease progression or therapeutic effect, cannot be used as the basis for early diagnosis or definite diagnosis of malignant tumors, and is not used for tumor screening of the general population.