This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Physiology
All are TRUE about protease activated receptors, EXCEPT: 
Select and explain. 
A. Family of three seven transmembrane protein, B. Activated by thrombin, C. Releases PGE2, D. Protects epithelial cells
A: Family of three seven transmembrane protein
Answer: A: Family of three seven transmembrane protein 
Explanation: Protease activated receptors (PARs), a family of four seven-transmembrane G protein-coupled receptors (PAR1, PAR2, PAR3, PAR4), act as targets for signalling by various proteolytic enzymes (thrombin, trypsin). PARs are characterized by a unique activation mechanism involving the proteolytic unmasking of a tethered ligand that stimulates the receptor. They release PGE2 and this inturn protects the epithelium. Ref: Ganong's Review of Medical Physiology, 21st Edition, Page 667