Inhibition of either β-arrestin or ERK augmented gefitinib to impair EMT, migration and proliferation in PC-9-GR cells (Figure 4E–P), revealing β-arrestin-ERK signaling as a principal pathway for targeting PAR2 in reversing gefitinib-resistant NSCLC cells. Here, F2RL1 is linked to non-small cell lung carcinoma.