F2RL1 and lung carcinoma: PAR2 blockade can significantly impair cell migration and EMT via ERK signaling in lung cancer (Tsai et al., 2018) whereas the dysregulation of ERK signaling and EMT are considered as molecular mechanisms of gefitinib resistance in NSCLC (Tricker et al., 2015; Becker et al., 2019; Weng et al., 2019), suggesting the potential involvement of PAR2-mediated signaling in lung tumor progression and drug resistance.