Final answer:
During metastasis, tumor cells protect themselves by associating with platelets and fibrinogen in the blood, not collagen, which is part of the extracellular matrix responsible for tissue formation and cell communication.
Step-by-step explanation:
To survive in the bloodstream during metastasis, tumor cells surround themselves with platelets and fibrinogen. While the extracellular matrix components such as collagen and proteoglycans play crucial roles in tissue formation and cell communication, in the context of metastasis, tumor cells utilize other components of the blood for protection.
The extracellular matrix (EMC) is significant as it connects cells to their external environment and is essential for the positioning of cells to prevent metastasis. However, during metastasis, tumor cells deploy a different strategy in the bloodstream. They co-opt cellular elements like platelets and coagulation factors such as fibrinogen to shield themselves, which facilitates their survival and enables them to evade the immune system. This mechanism does not rely on substances like collagen produced by the cells themselves but instead takes advantage of the blood's clotting processes.