TFLLR-NH2 is a protease-activated receptor (PARs) agonist which is more selective to PAR-1 than SFLLRN-NH2. Protease-activated receptors (PARs) are present on various organs including, plateles, mast cell, gallblader, oesophagus etc, and regulate various physiological processes including human platelet aggregation, vascular contraction/relaxation, and an increase in endothelial permeability. Recent papers indicated that PAR′s are also involved in sensory processing. Specificly PAR ligands enhance glutamatergic excitatory transmission in substantia gelatinosa (SG) neurons of adult rat spinal cord slices.