Macrophages are a diverse phenotype that has important functions in inherent and adaptive immunity. Macrophage ac-tivation has two distinct states of polarization:the classically activated (M1) and the alternatively activated (M2) macrophage pheno-types in different micro-environments. M2 macrophages exert an immuno-regulatory activity that is associated with the induction of Th2 responses. The macrophages can infiltrate in the tumor micro-environment, and is also known as tumor-associated macrophages (TAMs). TAMs show the M2 macrophage phenotypes that have been associated with tumor neo-vascularization, infiltration, and metas-tasis. This review aims to investigate the importance of the immuno-regulatory activity of TAM in the carcinogenesis of gastric cancers.

Cell therapy refers to a method that transplants stem cells or differentiated functioning cells into diseased regions to compensate the losing functions of diseased cells or uses the stem cells for treatment of diseases after in vitro genetic manipulation. After more than 30 years of study, great progress in hepatocyte transplantation technique has been acquired. This technique can acquire in situ liver transplantation effects. Hepatocyte transplantation, as an effective method for treatment of fulminant hepatic failure, has been widely confirmed in the animal model experiments and clinical practice. In addition, application of remedial hepatic stem cells can solve the problems regarding the source, number and immune rejection of hepatocytes, and offers a wide prospect for treatment of acute and chronic liver diseases. There are many problems about the study on hepatic stem cells. Up to date, many manuscripts addressing animal hepatic stem cell transplantation have been found, but few of them focus on the case report of treatment of liver disease by hepatocyte transplantation. Therefore, study on hepatic stem cells is still in its initial stage. The study methods should be developed and improved.