Abstract:Toll-like receptor 9 (TLR9) is a pattern recognition receptor, which can participate in the recognition of pathogen related molecular patterns (PAMPs). It is one of the important objects concerned by oncology and Immunology experts in recent years. The results show that TLR9 is abnormally expressed in many malignant tumor cells, and the activation of its signal transduction pathway plays an important role in promoting inflammatory response, apoptosis and tumor formation. It can also participate in the proliferation, migration, invasion and immune escape of tumor cells by promoting the formation of tumor microenvironment. This paper reviews the research progress of TLR9 and ovarian malignancies, cervical malignancies and endometrial malignancies.