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Medical AI Inquiry: You were designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.
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Which of the following is essential for tumor metastasis?
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The correct answer is  Metastasis is a complex series of steps in which cancer cells leave the original tumor site and migrate to other pas of the body the bloodstream or the lymphatic system. One of the critical events required for metastasis is the growth of a new network of blood vessels, called tumor angiogenesis.