AFP and viral infectious disease: Correlation analysis between the expression levels of MTP18 and clinicopathological features such as age, gender, virus infection, serum alpha fetoprotein (AFP), tumor size, TNM stage and tumor differentiation showed that higher expression of MTP18 was significantly associated with higher incidence of portal vein tumor thrombosis (PVTT) and larger tumor size, while no correlation was found between the expression levels of MTP18 and other clinicopathological features (Table 1).