CEACAM5 and neoplasm: The serum tumor markers detected in this examination mainly included carcinoembryonic antigen (CEA) 4.72 μg/L (normal reference value <5 μg/L), squamous cell carcinoma antigen (SCC) 0.45 μg/L (normal reference value <1.5 μg/L), cytokeratin 19 fragment (CYFRA21-1) 1.2 μg/L (normal reference value <3.3 μg/L), etc. The levels of these markers were all within the normal ranges.