F2RL1 and arthritic joint disease: Although the activation of PAR2 can reduce damage caused by arthritis, ARDS, and ischemia (McLean et al., 2002; McCulloch et al., 2018; White et al., 2018), the activation of PAR2 can lead to unwanted effects such as fetal injury, fibrosis, and inflammatory, metabolic and cardiovascular disorders (Cicala, 2002; Redecha et al., 2008; Grimsey et al., 2011; Kagota et al., 2016; Shearer et al., 2016; Heuberger and Schuepbach, 2019).