In patients 7 and 19 in our study, the evolution of PIVKA II levels after OLT follows an ideal pattern, in which these levels decreased at 1 month post-transplant with respect to pre-transplant values, reflecting that the diseased liver of HCC patients is the source of production of this abnormal prothrombin molecule, and increased considerably at 6 months post-transplant, coinciding approximately with the detection of tumor recurrence by imaging in both patients. This evidence concerns the gene F2 and hepatocellular carcinoma.