Abstract: HSPA9 gene is over-expressed in a variety of tumors, and it has been proved to be highly correlated with the proliferation and invasion of tumor cells. In recent years, there have been several studies on the expression of the HSPA9 gene in tumors and the downstream pathways involved, and analysis of related clinical characteristics has suggested that the expression of HSPA9 can be used as an independent clinical predictor. This article reviews the research results on the expression and function of HSPA9 gene in tumors to provide a theoretical basis for HSPA9 gene as a target for targeted therapy in the future.