F2RL1 and non-small cell lung carcinoma: A study on expression analysis of 384 GPCRs in gefitinib resistance has also showed that the level of PAR2 expression was largely higher in gefitinib-resistant NSCLC cells than sensitive cells (Kuzumaki et al., 2012), further indicating that PAR2 might be positively related to the development of gefitinib resistance.