Cancer metastasis is the spread of cancer cells from the original site of the tumor to other parts of the body. This process is responsible for the vast majority of cancer-related deaths and is a major challenge in cancer treatment. Understanding the mechanisms of metastasis, including how cancer cells invade surrounding tissues, travel through the bloodstream or lymphatic system, and form secondary tumors in distant organs, is critical for developing more effective therapies to prevent and treat metastatic cancer. Researchers study factors such as tumor microenvironment, genetic mutations, immune response, and other biological processes involved in metastasis to identify new targets for treatment and improve patient outcomes.