Tumor metastasis is the process by which cancer cells spread from the primary tumor site to other parts of the body, where they can form secondary tumors. This is a complex and multi-step process that involves cancer cells breaking away from the primary tumor, entering the bloodstream or lymphatic system, and then establishing themselves in a new location. Metastasis is a major cause of cancer-related deaths, as these secondary tumors can be more difficult to treat than the primary tumor. Understanding the mechanisms of tumor metastasis is crucial for developing new strategies to prevent or treat cancer metastasis and improve patient outcomes. Researchers study various aspects of tumor metastasis, including the signaling pathways and molecular mechanisms that drive the process, the role of the tumor microenvironment, and potential therapeutic targets for metastatic cancer.