For example, in clinical medicine, certain biochemical markers (e.g., carbohydrate antigen 19-9 (CA19-9), cancer embryonic antigen (CEA), and alpha-fetoprotein (AFP)) are used for the early diagnosis of cancer and monitoring the effectiveness of treatment5,6, whereas myocardial injury markers (such as troponin and CK-MB) are used for the diagnosis of heart disease and evaluation of acute myocardial infarction7. The gene discussed is AFP; the disease is cancer.