Furthermore, the discovery that matriptase is involved in the pathogenesis of idiopathic pulmonary fibrosis (IPF) [115] led Bardou et al. to propose a mechanism by which matriptase overexpression in IPF drives fibro-proliferative pathway signalling through the activation of PAR2, which was supported by both a human and an experimental mouse model [116]. The gene discussed is F2RL1; the disease is idiopathic pulmonary fibrosis.