The overexpression of PAR2 in the synovium and surrounding periarticular tissues was associated to worsening of osteoarthritis, where PAR2 promoted the release of pro-inflammatory cytokines and matrix metalloproteinases (MMPs), resulting in tissue damage, swelling, granulocyte infiltration, and osteophyte formation (48, 49). Here, F2RL1 is linked to osteoarthritis.