**5.5 Hepatocyte growth factor (HGF)**

Hepatocyte growth factor (HGF) is a multifunctional element produced in many organs in the body, it affects cell division, cell motility, intracellular invasion, and carcinogenesis [86]. In a study in Japan, serum HGF levels are increased significantly in the HCC group compared with cirrhosis, chronic hepatitis and healthy controls groups. With a cutting level of 0.6 ng/ml, its sensitivity can be up to 100% for any AFP or DCP concentration. The serum HGF concentration ≥ 1.0 ng/ml has a shorter shelf life, so it can be used as a prognostic marker for HCC [87]. The authors suggest that HGF causes proliferation and invasion of cancer cells through the expression of c-met receptors. In addition, increased HGF serum levels along with high expression of serum c-met protein after hepatectomy play an important role in predicting tumor recurrence and metastasis. This can be explained by the fact that HGF can increase the production and size of both normal and malignant liver cells after surgery, leading to tumor recurrence [88].
