Background：Proteinase-activated receptors(PARs) are G protein-coupled receptors activated through cleavage of their N-termini by mainly serine proteases. The family of PARs include four members: PAR1, PAR2, PAR3 and PAR4. PAR2, also known as F2RL1, is expressed in epithelial cells(e.g., lung, gastrointestinal tract), endothelial cells, smooth muscle cells, fibroblasts, nerves, and some immune and inflammatory cells. PAR2 knockout mice and PAR2 agonists and antagonists have implicated PAR2 as a promising target in inflammatory conditions; respiratory, gastrointestinal, metabolic, cardiovascular, and neurological dysfunction; and cancers.(PMID:23895492)
