Increase in GGT levels was also found to significantly correlate with an increase in maximum tumor diameter from 4.5 to 7 cm, a 20-fold increase in serum alpha-fetoprotein level, an increase in tumor multifocality from 20 to 54% of patients, and a doubling in percent of patients with portal vein thrombosis (PVT) from 20 to 40%. This evidence concerns the gene AFP and Portal vein thrombosis.