AFP is a glycoprotein originally identified as the first oncoprotein and is now widely used as a biomarker in hepatocellular carcinoma screening (45, 46), Elevated serum AFP levels have also been reported in some patients with primary lung cancer (47, 48), and extremely high concentrations are a distinguishing feature of hepatoid adenocarcinoma of the lung (49), However, the intrinsic relationship between AFP and lung adenocarcinoma remains poorly understood and warrants further investigation. Here, AFP is linked to lung carcinoma.