Abstract: Hepatocellular carcinoma (HCC) is the most frequent malignancy of the liver. Transforming growth factor beta 1 (TGFB1 ) and marker of proliferation Ki-67 (MKI67 ) regulate cell proliferation, differentiation, and growth. The association between MKI67 and TGFB1 expression and its clinical implications in HCC remain unknown.
Methods: Public databases were used to analyze TGFB1 and MKI67 expression in different pathologic grades/stages and tissue types of HCC. The association between MKI67 and TGFB1 expression was explored using pathway analysis and in a HepG2 cell line treated with TGFB1. Survival analysis was performed to evaluate the prognostic value of TGFB1 and MKI67 expression in patients with hepatitis B virus (HBV)-related HCC. 
Results: We identified that MKI67 expression was upregulated in liver cancer tissues. MKI67 and TGFB1 expression levels were different in various stages and tissue types of liver cancer. Furthermore, MKI67 expression was associated with TGFB1 expression in liver cancer tissues and HepG2 cells. Patients with HBV-related HCC and a higher level of MKI67 expression had a worse prognosis. Moreover, a nomogram was conducted to predict the clinical outcomes of patients with HBV-related HCC. 
Conclusion: MKI67 expression level was associated with TGFB1 expression in liver cancer tissues and a HepG2 cell line. MKI67 expression level can predict the clinical outcomes of patients with HBV-related HCC.
Keywords: MKI67, TGFB1, HBV-related HCC, nomogram