New Cellular Source of TF (Tissue Factor)-Positive Extracellular Vesicles in the Circulation

Exosomes are stable, lipid bilayer-enclosed vesicles capable of crossing biological barriers. They can carry a wide range of molecules required for intercellular communication. Once exosomes are released from the cell where they originated, they enter a recipient cell through various pathways such as fusion, receptor-mediated endocytosis, macropinocytosis, and phagocytosis.
Stahl et al. discovered exosomes in 1983, but the exosomes were initially considered waste products released from the...

Blood clotting or coagulation involves extrinsic and intrinsic pathways, which ultimately merge into the common pathway, forming a fibrin clot.
The Extrinsic Pathway
The extrinsic pathway of coagulation is typically initiated by tissue damage that exposes blood to tissue factor (TF), a protein released by the damaged tissue cells outside the blood vessels—this interaction with TF triggers biochemical reactions involving specific clotting factors. The key player here is Factor VII, which...