However, the wild-type p53 product in the cell is very low, extremely unstable, and has a short half-life of only a few minutes, so it cannot be detected at all), as well as GPC3, CK19, and Ki67 in liver tumor tissues, and significantly elevated serum levels of tumor markers, including AFP, CA125, and CA19-9. The gene discussed is GPC3; the disease is neoplasm.