Human peripheral blood monocytes express protease receptor-2 and respond to receptor activation by production of IL-6, IL-8, and IL-1{beta}.

Protease-activated receptor-2 (PAR-2) belongs to a family of G-coupled receptors activated by proteolytic cleavage to reveal a tethered ligand. PAR-2 is activated by trypsin and trypsin-like serine proteases and experimentally, by receptor-activating peptides (APs), which mimic the tethered ligand. PAR-2 has recently been implicated in proinflammatory immune responses.