EGFR and lung cancer: EGFR mutation or amplification are frequently detected in lung cancer; and studies suggest that activation of TGF-β pathway is associated with EGFRi/EGFR tyrosine kinase inhibitor (TKI)/cetuximab resistance (Yao et al., 2010; Bedi et al., 2012; Kurimoto et al., 2016; Li et al., 2016; Du et al., 2020; Kuo et al., 2020; Qiu et al., 2020).