Which protein serves as a marker elevated in hepatocellular carcinoma?

• A. a1-Fetoprotein
• B. Carcinoembryonic antigen
• C. Alpha1-antitrypsin
• D. Beta2-microglobulin

Answer: (A)

Alpha-fetoprotein is the protein classically used as a marker for hepatocellular carcinoma. AFP is normally produced by fetal liver tissue, so it is high before birth and drops after birth. In adults, an elevated AFP level suggests hepatocellular carcinoma because malignant hepatocytes often produce AFP. It can also be elevated in certain germ cell tumors, which is why the clinical context matters. The other proteins listed aren’t specific markers for liver cancer: carcinoembryonic antigen is more linked to colorectal and other cancers, alpha-1 antitrypsin is a protease inhibitor produced by the liver without being a cancer marker, and beta-2 microglobulin rises in some hematologic cancers and kidney issues but not as a primary indicator of hepatocellular carcinoma.