A recent study collected six serum tumor markers, including alpha-fetoprotein (AFP), carcinoembryonic antigen (CEA), cancer antigen 19-9 (CA19-9), cancer antigen 72-4 (CA72-4), cytokeratin 19 fragment 21-1 (Cyfra21-1) and neuron-specific enolase (NSE), and compared the distribution of all these serum tumor markers in the study participants. The gene discussed is AFP; the disease is neoplasm.